Other Items . Foreign exchange gains increased approximately $3.6 million during fiscal 2009 as compared  to fiscal 2008 due to a stronger U.S. dollar relative to other currencies.  Insurance and loss reserves decreased approximately 46%, or $10.9 million, during fiscal 2009 as  compared to 2008, due to lower premiums and loss reserves recorded as a result of a better safety record  during fiscal 2009 as compared to fiscal 2008.  Gain on asset dispositions, net, increased approximately $15.8 million, or 138%, during fiscal 2009 as  compared to fiscal 2008, due to a higher number of vessels sold during fiscal 2009 and due to larger gains  earned on the mix of vessels sold. Vessel utilization is determined primarily by market conditions and to a lesser extent by drydocking  requirements. Vessel day rates are determined by the demand created largely through the level of offshore  exploration, field development and production spending by energy companies relative to the supply of  offshore service vessels. Suitability of equipment and the degree of service provided also influence vessel  day rates. Vessel utilization rates are calculated by dividing the number of days a vessel works during a  reporting period by the number of days the vessel is available to work in the reporting period. Average day  rates are calculated by dividing the revenue a vessel earns during a reporting period by the number of days  the vessel worked in the reporting period. Vessel utilization and average day rates are calculated only on  vessels in service and, as such, do not include vessels withdrawn from service or joint venture vessels. The  following tables compare revenues, day-based utilization percentages and average day rates by vessel  class and in total for each of the quarters in the years ended March 31:  -40-  Vessel Class Revenue and Statistics by Segment 