I am new to Excel but am using it to help evaluate real estate property
values. One of the ways I evaluate a property is to look at a
neighborhood's appreciation rates and then calculate a houses current
market value (roughly) based on appreciation rates obtained from a
subscription service and sales history. The problem I have is the
appreciation rates are provides as a gross appreciation rate from 1990
to present and my data for a given property is for some subsection of
that time (say from 1995); therefore, I need to break the gross
appreciation rate down into an annual compound interest rate.

Given a gross appreciation rate over a given period of time (say, 87%
over 15 years), how can I calculate the annual compound appreciation
rate?

Thanks,
Dave