Calculating business growth

[#1]

Hi,

Not sure if anyone will be able to answer this but I will try to explain the best I can.  I need to calculate business growth and ideally show this on a bar chart, I want to be able to say:

if financial year = 147 sum sales MINUS if financial year = 146 sum sales.  Then DIVIDE financial year = 146 sum sales

(Example:

146 = 300,000

147 = 250,000

Business Growth = -16.76%)

[#2]

Does anyone know of an expression I can use?

[#3]

Try

(sum({1<'Financial Year' = {147}>}sales) - sum{1<'Financial Year' = {146}>}sales))/(sum{1<'Financial Year' = {146}>}sales))