Detecting patters in data
 

I'm working on a project that requires me to detect patterns in certain data.
The data consists of monthly jet fuel prices from 1994-2006. I need to
detect the periods when the prices are increasing, and when they are
decreasing. It would make my life so much easier if there is a function in
Excel that allows me to detect these patterns automatically (e.g. so I don't
have to pick them out visually with a chart).