Our leases expire from 2011 through 2018 and have an average term of four years, although our typical lease term ranges from three to five years. We believe we will not have any difficulty obtaining renewals of leases as they expire or, alternatively, leasing comparable properties. The aggregate annual rent expense under all leases was approximately $45.2 million in 2010.
Investment income. Investment income decreased $2.4 million, or 11.6%, and $8.3 million, or 28.5%, in 2010 and 2009, respectively. The decrease in 2010 was primarily due to decreases in yield. The decreases were partially offset by a one-time royalty payment of $1.2 million received in June 2010. The decrease in 2009 was also primarily due to decreases in the average invested balances and, to a lesser extent, decreases in yield.
Provisions for title losses in 2010 also include charges of $13.3 million (0.09% of title revenues) resulting from changes in the estimated legal costs for several existing large title claims. These charges were partially offset by insurance recoveries of $2.8 million (0.01% of title revenues) on previously recognized title losses. We had no agency defalcation losses exceeding $1.0 million during 2010 and only five such claims reported (averaging less than $1.5 million each) in the previous six quarters.
The year ended December 31, 2009 included reserve strengthening adjustments of $32.7 million (2.0% of title revenues) relating to policy years 2005, 2006 and 2007 due to higher than expected loss payments and incurred loss experience for these policy years. The increase in loss payment experience for recent policy years resulted in an increase in the loss ratio related to revenues recognized on policies issued in 2009, and, accordingly, a $3.8 million catch-up adjustment was recorded to title losses in the third quarter of 2009. Provisions for title losses in 2009 also include charges of $31.8 million (2.0% of title revenues) relating to large title claims including several independent agency defalcations and mechanic lien claims. These charges were partially offset by insurance recoveries of $11.9 million (0.7% of title revenues) on previously recognized title losses.
Excluding the impact of the reserve strengthening charges, large losses, and defalcations (net of recoveries), title losses as a percent of title revenues were 8.6%, 8.0% and 7.1% in 2010, 2009 and 2008, respectively. Cash claims payments remained elevated in 2010, and consequently, we maintained a relatively high provisioning rate for title losses. Nonetheless, we believe we are on track to return to a normal loss ratio by the end of 2012.
On September 30, 2008, we entered into a $241.5 million line of credit agreement with a bank from which we had acquired auction rate securities. The line of credit was a demand loan in an amount equal to the full par value of the auction rate securities that secured the loan. On June 30, 2010, we exercised our ability to relinquish and transfer all rights to the auction rate securities to the bank, at par value in accordance with the line of credit agreement, at which time the bank extinguished the outstanding balance of the line of credit. There was no net impact to our consolidated financial statements as of and for the year ended December 31, 2010 as a result of the exercise of our rights under this agreement.
The effect of changes in foreign currency rates on the consolidated statements of cash flows was a net increase in cash and cash equivalents of $0.8 million and $5.2 million in 2010 and 2009, respectively, as compared to a net decrease of $11.2 million in 2008. Our principal foreign operating unit is in Canada, and the value of the U.S. dollar relative to the Canadian dollar increased during 2010.