Errata....

On Sep 30, 4:49 pm, I wrote:
So you can write the following formulas (suppose you have 7
years of quarterly data in Y1:Y28):
=(Y28/$Y$1)^(4/count($Y$1:Y28)) - 1

I believe that should be 4/(count($Y$1:Y28)-1). That off-by-one error
carries through my entire previous explanation. That is, if you have
N data points, you divide by N-1.