Data in my table includes the folliwing information - the sales by week are cummulative ( I cant change the way that that happens)
Type, week1, week2, week3, week4
cars, 1, 3, 5,
bikes, 1, 2,
trikes, 0, 1, 2, 5,
I need to be able to get the data for any week as examples below.
Sales at...