3.6 The summarized results of Louis’s business for the 3 years to the end of 2012 were as follows:

2012 2011 2010

£ £ £

Revenue 291 318 282 400 269 340 Cost of sales (213 916) (206 420) (196 071)

Gross profit 77 402 75 980 73 269 Expenses (52 394) (51 720) (49 270)

Net profit 25 008 24 260 23 999 Calculate the gross and net profit margins for each year and comment briefly on the general trends in the business trading results.