Filter in columns or measures (revenue previous year)

Hello!

In Crystal Reports 2008, I desinged a producthierarchy which shows values of revenues.

The Report is build on a BEx Query. The BEx Query has only the measure "revenue".

So far, this works fine...!

Now, I want to add 2 additional measures (columns) to my report: "revenue previous year" and "revenue per month".

How can I implement that?

How does it work? Formulas? Filters?

________________Revenue Total____revenue previous year______revenue per month

vehicles____________18.000u20AC_________?______________________?________

____cars___________ 15.000u20AC_________?______________________?_______

_______Mercedes____10.000u20AC_________?______________________?_______

_______BMW________5.000u20AC_________?______________________?_________

____bicycles_________3.000u20AC_________?_______________________?________

_______Allroundbike__1.000u20AC__________?_______________________?________

_______Mountainbike_ 2.000u20AC_________?________________________?________

Thanks!

Maximilian