Depreciation of revenue earning equipment and lease charges includes the following (in millions of dollars):

	Three Months Ended March 31,

	2012			2011
Depreciation of revenue earning equipment	$	530.4		$	418.7
Adjustment of depreciation upon disposal of revenue earning equipment		(39.4	)		(6.2	)
Rents paid for vehicles leased		23.1			23.6

Total	$	514.1		$	436.1

The adjustment of depreciation upon disposal of revenue earning equipment for the three months ended March 31, 2012 and 2011, included net gains of $34.9 million and $6.1 million, respectively, on the disposal of vehicles used in our car rental operations and a gain of $4.5 million and a net gain of $0.1 million, respectively, on the disposal of industrial and construction equipment used in our equipment rental operations.

Depreciation rates are reviewed on a quarterly basis based on management's routine review of present and estimated future market conditions and their effect on residual values at the time of disposal. During the three months ended March 31, 2012, depreciation rates being used to compute the provision for depreciation of revenue earning equipment were adjusted on certain vehicles in our car rental operations to reflect changes in the estimated residual values to be realized when revenue earning equipment is sold. These depreciation rate changes resulted in a net decrease of $0.2 million in depreciation expense for the three months ended March 31, 2012.

For the three months ended March 31, 2012 and 2011, our worldwide car rental operations sold approximately 40,000 and 30,600 non-program cars, respectively, a 30.6% year over year increase primarily due to an overall increase in the number of cars in the fleet, an increase in the percentage of non-program cars, and a robust used car market. We believe the positive trending of residual values is primarily due to continued short supply of used vehicle inventory and improving consumer confidence. This, along with an overall strong car sales market (with fewer incentives on new vehicle sales), is expected to keep the demand for nearly new used vehicles on a positive trend for the near term.