a:4:{i:0;a:3:{i:0;s:51:"The method of calculating the fuel consumption rate";i:1;d:0;i:2;i:0;}i:1;a:3:{i:0;s:90:"The method of calculating depreciation at a uniform rate over the useful life of a machine";i:1;d:0;i:2;i:1;}i:2;a:3:{i:0;s:47:"The method of estimating wear and tear on tires";i:1;d:0;i:2;i:0;}i:3;a:3:{i:0;s:67:"The method of spreading the storage cost evenly across all machines";i:1;d:0;i:2;i:0;}}