What is Trend Forecasting? Is there any formula or method to project future sales on basis of given set of data? Data is given in the file attached.636

This looks like a math question. If you look at the pattern in the data you can extrapolate what the 1996 sales should be.

In the real world, it's not quite that straight forward. Check out:
http://www.entrepreneur.com/article/0,4621,289242,00.html