6 Month Forecast!!!??

[dansalmada]

I have a table with Forecasted Sales:

Month Value
2004/01 600
2004/02 1,200
2004/03 695
2004/04 3945
2004/05 500

Then I have a query which copies [Forecasted Sales] into another line in the next month so I can divide both values and get a change percentage

Month Forecasted Sales Prior Sales Change %
2004/01 600 0 0%
2004/02 1,200 600 200%
2004/03 695 1200 58%
2004/04 3945 695 567%
2004/05 500 3945 13%
2004/06 500

I also have a Real Sales Table with one value loaded which I need to multiply by the change % obtained on the last query

Month Real Sale Change %
2004/01 1,100 0
2004/02 2,200 200%
2004/03 58%
2004/04 567%
2004/05 13%

The problem is when I try to obtain the values for 2004/03 through 2004/05
I can only get the first value 2004/02 but then it won't "run" through to the next month

Can anyone help me pleaseE???

Thanks