Marketable Securities

6 Months Ended

Sep. 30, 2011

NOTE 5. MARKETABLE SECURITIES
Marketable securities with remaining maturities less than one year are classified as short-term, and those with remaining maturities greater than one year are classified as long-term. The fair value of our marketable securities as of September 30, 2011, by maturity, were as follows:

Total			<1 Year			1–3 Years			3–5 Years
$	66,272,362		$	11,122,455		$	25,668,319		$	29,481,588

As of September 30 and March 31, 2011, our marketable securities were as follows:

	As of September 30, 2011									As of March 31, 2011
	Adjusted Cost		Gross Unrealized Gains		Gross Unrealized Losses			Fair Market Value		Adjusted Cost		Gross Unrealized Gains		Gross Unrealized Losses			Fair Market Value
U.S. agency securities	$	-	$	-	$	-		$	-	$	83,358	$	1,200	$	-		$	84,558
Corporate bonds		43,827,332		937,914		(437,622	)		44,327,624		37,884,146		1,231,743		(147,443	)		38,968,446
Municipal bonds	21,439,498		523,744		(18,504		)	21,944,738		21,582,084		602,457		(10,047		)	22,174,494
Total	$	65,266,830	$	1,461,659	$	(456,126	)	$	66,272,362	$	59,549,588	$	1,835,400	$	(157,490	)	$	61,227,498

The following table shows the gross unrealized losses and fair value of our investments with unrealized losses, aggregated by investment category and length of time that individual securities had been in a continuous unrealized loss position as of September 30 and March 31, 2011:

		Less Than 12 Months							12 Months or Greater						Total
		Fair Market Value			Gross Unrealized Losses				Fair Market Value			Gross Unrealized Losses			Fair Market Value			Gross Unrealized Losses
As of September 30, 2011
	U.S. agency securities	$	-		$	-			$	-		$	-		$	-		$	-
	Corporate bonds	16,276,873		(437,622			)	-			-			16,276,873			(437,622			)
	Municipal bonds	1,798,229			(18,504		)		-			-			1,798,229			(18,504		)
	Total	$	18,072,102		$	(456,126	)		$	-		$	-		$	18,072,102		$	(456,126	)
As of March 31, 2011
	U.S. agency securities	$	-		$	-			$	-		$	-		$	-		$	-
	Corporate bonds	9,146,952		(147,443			)	-			-			9,146,952			(147,443			)
	Municipal bonds	2,178,225			(10,047		)		-			-			2,178,225			(10,047		)
	Total	$	11,325,177		$	(157,490	)		$	-		$	-		$	11,325,177		$	(157,490	)

Gross unrealized losses totaled $456,126 as of September 30, 2011, and were attributable to seven corporate and two municipal bonds out of a portfolio of 54 bonds. Corporate bonds accounted for $437,622 of the total gross unrealized losses. The gross unrealized losses were due to market-price decreases and rating downgrades after the bonds were purchased. None of the bonds we hold had been in a continuous unrealized loss position for 12 months or more. Although several of the bonds we held were downgraded by Moody's or Standard and Poor's during the quarter ended September 30, 2011, all of the bonds that were rated by Moody's or Standard and Poor's had investment-grade credit ratings. For each bond with an unrealized loss, we expect to recover the entire cost basis of each security based on our consideration of factors including their credit ratings, the underlying ratings of insured bonds, and historical default rates for securities of comparable credit rating. Because we expect to recover the entire cost basis of the securities, and because we do not intend to sell the securities and it is not more likely than not that we will be required to sell the securities before recovery of the cost basis, which may be maturity, we did not consider any of our marketable securities to be other-than-temporarily impaired at September 30, 2011.