In a message dated 1/29/2005 6:18:42 PM Central Standard Time, email@example.com writes:
From Excel file, with Excel automatically fitted linear trendline
Excellent work. When you get the additional membership data you will be able to do some statistical analysis.
To plot trend lines with which to do statistical prediction/analysis or hypothesis testing you most often plot the trend lines between peaks and valleys. The trend line you have plotted indicates were we are versus where we would have been had the historical trend continued.
It would be most interesting too, to look at what occured in our history at each of these peaks and valleys.