A depreciation schedule for semi-trucks of Ichiro Manufacturing Company was requested by your auditor soon after December 31, 2013, showing the additions, retirements, depreciation, and other data affecting the income of the company in the 4-year period 2010 to 2013, inclusive. The following data were ascertained. Balance of Trucks account, Jan. 1, 2010 Truck No. 1 purchased Jan. 1, 2007, cost $27,900 Truck No. 2 purchased July 1, 2007, cost 34,100 Truck No. 3 purchased Jan. 1, 2009, cost 46,500 Truck No. 4 purchased July 1, 2009, cost 37,200 Balance, Jan. 1, 2010 $145,700 The Accumulated DepreciationTrucks account previously adjusted to January 1, 2010, and entered in the ledger, had a balance on that date of $46,810 (depreciation on the four trucks from the respective dates of purchase, based on a 5-year life, no salvage value). No charges had been made against the account before January 1, 2010. Transactions between January 1, 2010, and December 31, 2013, which were recorded in the ledger, are as follows. July 1, 2010 Truck No. 3 was traded for a larger one (No. 5), the agreed purchase price of which was $62,000. Ichiro Mfg. Co. paid the automobile dealer $34,100 cash on the transaction. The entry was a debit to Trucks and a credit to Cash, $34,100. The transaction has commercial substance. Jan. 1, 2011 Truck No. 1 was sold for $5,425 cash; entry debited Cash and credited Trucks, $5,425. July 1, 2012 A new truck (No. 6) was acquired for $65,100 cash and was charged at that amount to the Trucks account. (Assume truck No. 2 was not retired.) July 1, 2012 Truck No. 4 was damaged in a wreck to such an extent that it was sold as junk for $1,085 cash. Ichiro Mfg. Co. received $3,875 from the insurance company. The entry made by the bookkeeper was a debit to Cash, $4,960, and credits to Miscellaneous Income, $1,085, and Trucks, $3,875. Entries for depreciation had been made at the close of each year as follows: 2010, $32,550; 2011, $34,875; 2012, $38,828; 2013, $47,120. (a) For each of the 4 years, compute separately the increase or decrease in net income arising from the companys errors in determining or entering depreciation or in recording transactions affecting trucks, ignoring income tax considerations. (Enter Credit amounts and Understated Income amounts with a negative sign preceding the number, e.g. -2,520 or in parenthesis, e.g. (2,520).)