Calculate the missing figures in the table below. Show all working

Figures are in thousands

Account	2015	2014	2013
Salaries Payable	375	425	475
Cost of goods sold	3360	2987
Prepaid insurance	87	119	112
Working capital	?	?
Depreciation expense	250	325
Note payable due Dec 31 2029	900	750	600
Net income	1279	1540	1138
Accumulated depreciation	835	725	600
Accounts Receivable	1128	833	851
Common Stock	525	450	400
Sales	?	?
Income tax expense	?	?
Accounts payable	658	535	485
Inventory	595	438	179
Acid test ratio	?	?
Plant and equipment	3078	3031	2012
Dividends paid	?	?
Gross Profit %	52.00%	59.38%
Insurance expense	100	135
Debt to Equity Ratio	?	?
Net profit %	?	?
Income taxes payable	225	250	175
Administrative and other expense	1766	2110
Return on Total Assets	?	?
Interest Coverage	9.63 times	9.52 times
Current Ratio	1.48:1	1.38:1
Cash	?	?	632
Return on Equity	?	?
Debenture	164	221	188
Retained earnings	2003	1910	863
Additional Information
1	Inventory - Traditionally 20% of the inventory is normally used after 1 year of being in stock.
2	Note Payable - 15%, 35% and 40% of the balance reflected at the end of the years 2013, 2014, and 2015 respectively is due in the following year for repayment.
3	Interest Expense - It is included as part of administrative and other expense, and represents 10% of the total cost for the year.