<informationTable xmlns="http://www.sec.gov/edgar/document/thirteenf/informationtable">		<infoTable>
			<nameOfIssuer>INVESCO QQQ TR</nameOfIssuer>
			<titleOfClass>UNIT SER 1</titleOfClass>
			<cusip>46090E103</cusip>
			<value>196257</value>
			<shrsOrPrnAmt>
				<sshPrnamt>1030764</sshPrnamt>
				<sshPrnamtType>SH</sshPrnamtType>
			</shrsOrPrnAmt>
			<investmentDiscretion>SOLE</investmentDiscretion>
			<votingAuthority>
				<Sole>1030764</Sole>
				<Shared>0</Shared>
				<None>0</None>
			</votingAuthority>
		</infoTable>
		<infoTable>
			<nameOfIssuer>ISHARES TR</nameOfIssuer>
			<titleOfClass>MSCI MIN VOL ETF</titleOfClass>
			<cusip>46429B697</cusip>
			<value>392739</value>
			<shrsOrPrnAmt>
				<sshPrnamt>7276320</sshPrnamt>
				<sshPrnamtType>SH</sshPrnamtType>
			</shrsOrPrnAmt>
			<investmentDiscretion>SOLE</investmentDiscretion>
			<votingAuthority>
				<Sole>7276320</Sole>
				<Shared>0</Shared>
				<None>0</None>
			</votingAuthority>
		</infoTable>
		<infoTable>
			<nameOfIssuer>ISHARES TR</nameOfIssuer>
			<titleOfClass>CORE S&amp;P500 ETF</titleOfClass>
			<cusip>464287200</cusip>
			<value>300928</value>
			<shrsOrPrnAmt>
				<sshPrnamt>1165800</sshPrnamt>
				<sshPrnamtType>SH</sshPrnamtType>
			</shrsOrPrnAmt>
			<investmentDiscretion>SOLE</investmentDiscretion>
			<votingAuthority>
				<Sole>1165800</Sole>
				<Shared>0</Shared>
				<None>0</None>
			</votingAuthority>
		</infoTable>
		<infoTable>
			<nameOfIssuer>MARSH &amp; MCLENNAN COS INC</nameOfIssuer>
			<titleOfClass>COM</titleOfClass>
			<cusip>571748102</cusip>
			<value>453517</value>
			<shrsOrPrnAmt>
				<sshPrnamt>5245400</sshPrnamt>
				<sshPrnamtType>SH</sshPrnamtType>
			</shrsOrPrnAmt>
			<investmentDiscretion>SOLE</investmentDiscretion>
			<votingAuthority>
				<Sole>5245400</Sole>
				<Shared>0</Shared>
				<None>0</None>
			</votingAuthority>
		</infoTable>
		<infoTable>
			<nameOfIssuer>PRINCIPAL FINL GROUP INC</nameOfIssuer>
			<titleOfClass>COM</titleOfClass>
			<cusip>74251V102</cusip>
			<value>568414</value>
			<shrsOrPrnAmt>
				<sshPrnamt>18137000</sshPrnamt>
				<sshPrnamtType>SH</sshPrnamtType>
			</shrsOrPrnAmt>
			<investmentDiscretion>SOLE</investmentDiscretion>
			<votingAuthority>
				<Sole>18137000</Sole>
				<Shared>0</Shared>
				<None>0</None>
			</votingAuthority>
		</infoTable>
		<infoTable>
			<nameOfIssuer>PRUDENTIAL FINL INC</nameOfIssuer>
			<titleOfClass>COM</titleOfClass>
			<cusip>744320102</cusip>
			<value>133478</value>
			<shrsOrPrnAmt>
				<sshPrnamt>2560000</sshPrnamt>
				<sshPrnamtType>SH</sshPrnamtType>
			</shrsOrPrnAmt>
			<investmentDiscretion>SOLE</investmentDiscretion>
			<votingAuthority>
				<Sole>2560000</Sole>
				<Shared>0</Shared>
				<None>0</None>
			</votingAuthority>
		</infoTable>
		<infoTable>
			<nameOfIssuer>SPDR DOW JONES INDL AVRG ETF</nameOfIssuer>
			<titleOfClass>UT SER 1</titleOfClass>
			<cusip>78467X109</cusip>
			<value>84716</value>
			<shrsOrPrnAmt>
				<sshPrnamt>387700</sshPrnamt>
				<sshPrnamtType>SH</sshPrnamtType>
			</shrsOrPrnAmt>
			<investmentDiscretion>SOLE</investmentDiscretion>
			<votingAuthority>
				<Sole>387700</Sole>
				<Shared>0</Shared>
				<None>0</None>
			</votingAuthority>
		</infoTable>
		<infoTable>
			<nameOfIssuer>SELECT SECTOR SPDR TR</nameOfIssuer>
			<titleOfClass>SBI INT-INDS</titleOfClass>
			<cusip>81369Y704</cusip>
			<value>109760</value>
			<shrsOrPrnAmt>
				<sshPrnamt>1861600</sshPrnamt>
				<sshPrnamtType>SH</sshPrnamtType>
			</shrsOrPrnAmt>
			<investmentDiscretion>SOLE</investmentDiscretion>
			<votingAuthority>
				<Sole>1861600</Sole>
				<Shared>0</Shared>
				<None>0</None>
			</votingAuthority>
		</infoTable>
		<infoTable>
			<nameOfIssuer>SELECT SECTOR SPDR TR</nameOfIssuer>
			<titleOfClass>TECHNOLOGY</titleOfClass>
			<cusip>81369Y803</cusip>
			<value>126236</value>
			<shrsOrPrnAmt>
				<sshPrnamt>1569900</sshPrnamt>
				<sshPrnamtType>SH</sshPrnamtType>
			</shrsOrPrnAmt>
			<investmentDiscretion>SOLE</investmentDiscretion>
			<votingAuthority>
				<Sole>1569900</Sole>
				<Shared>0</Shared>
				<None>0</None>
			</votingAuthority>
		</infoTable>
		<infoTable>
			<nameOfIssuer>SELECT SECTOR SPDR TR</nameOfIssuer>
			<titleOfClass>SBI CONS STPLS</titleOfClass>
			<cusip>81369Y308</cusip>
			<value>144993</value>
			<shrsOrPrnAmt>
				<sshPrnamt>2659930</sshPrnamt>
				<sshPrnamtType>SH</sshPrnamtType>
			</shrsOrPrnAmt>
			<investmentDiscretion>SOLE</investmentDiscretion>
			<votingAuthority>
				<Sole>2659930</Sole>
				<Shared>0</Shared>
				<None>0</None>
			</votingAuthority>
		</infoTable>
		<infoTable>
			<nameOfIssuer>SELECT SECTOR SPDR TR</nameOfIssuer>
			<titleOfClass>SBI HEALTHCARE</titleOfClass>
			<cusip>81369Y209</cusip>
			<value>147738</value>
			<shrsOrPrnAmt>
				<sshPrnamt>1668600</sshPrnamt>
				<sshPrnamtType>SH</sshPrnamtType>
			</shrsOrPrnAmt>
			<investmentDiscretion>SOLE</investmentDiscretion>
			<votingAuthority>
				<Sole>1668600</Sole>
				<Shared>0</Shared>
				<None>0</None>
			</votingAuthority>
		</infoTable>
		<infoTable>
			<nameOfIssuer>SELECT SECTOR SPDR TR</nameOfIssuer>
			<titleOfClass>SBI CONS DISCR</titleOfClass>
			<cusip>81369Y407</cusip>
			<value>100215</value>
			<shrsOrPrnAmt>
				<sshPrnamt>1022600</sshPrnamt>
				<sshPrnamtType>SH</sshPrnamtType>
			</shrsOrPrnAmt>
			<investmentDiscretion>SOLE</investmentDiscretion>
			<votingAuthority>
				<Sole>1022600</Sole>
				<Shared>0</Shared>
				<None>0</None>
			</votingAuthority>
		</infoTable>
		<infoTable>
			<nameOfIssuer>SPDR S&amp;P 500 ETF TR</nameOfIssuer>
			<titleOfClass>TR UNIT</titleOfClass>
			<cusip>78462F103</cusip>
			<value>267296</value>
			<shrsOrPrnAmt>
				<sshPrnamt>1037077</sshPrnamt>
				<sshPrnamtType>SH</sshPrnamtType>
			</shrsOrPrnAmt>
			<investmentDiscretion>SOLE</investmentDiscretion>
			<votingAuthority>
				<Sole>1037077</Sole>
				<Shared>0</Shared>
				<None>0</None>
			</votingAuthority>
		</infoTable>
		<infoTable>
			<nameOfIssuer>VANGUARD INDEX FDS</nameOfIssuer>
			<titleOfClass>S&amp;P 500 ETF SHS</titleOfClass>
			<cusip>922908363</cusip>
			<value>310689</value>
			<shrsOrPrnAmt>
				<sshPrnamt>1313749</sshPrnamt>
				<sshPrnamtType>SH</sshPrnamtType>
			</shrsOrPrnAmt>
			<investmentDiscretion>SOLE</investmentDiscretion>
			<votingAuthority>
				<Sole>1313749</Sole>
				<Shared>0</Shared>
				<None>0</None>
			</votingAuthority>
		</infoTable>
		<infoTable>
			<nameOfIssuer>VANGUARD INDEX FDS</nameOfIssuer>
			<titleOfClass>TOTAL STK MKT</titleOfClass>
			<cusip>922908769</cusip>
			<value>313778</value>
			<shrsOrPrnAmt>
				<sshPrnamt>2432200</sshPrnamt>
				<sshPrnamtType>SH</sshPrnamtType>
			</shrsOrPrnAmt>
			<investmentDiscretion>SOLE</investmentDiscretion>
			<votingAuthority>
				<Sole>2432200</Sole>
				<Shared>0</Shared>
				<None>0</None>
			</votingAuthority>
		</infoTable>
</informationTable>
