Income taxes



	For the three months ended March 31
(in millions of Canadian dollars)	2016		2015
Current income tax expense	$	77	$	102
Deferred income tax expense	93		32
Income tax expense	$	170	$	134

The estimated 2016 annual effective tax rate for the first quarter, excluding the discrete item related to the foreign exchange gain of $181 million on the Company’s U.S. dollar-denominated debt, is 27.5%, similar to the estimate of 27.5% for the same period in 2015.

The effective tax rate in the first quarter, including discrete item, is 23.9%, compared to 29.5% for the same period in 2015.