I currently have the following (simplified) raw data:

```
Metric Value Year
Units 500 2009
Cost 1200 2009
Units 600 2010
Cost 1500 2010
Units 1000 2011
Cost 1600 2011
```

In a pivot table like:

```
2009 2010 2011
Units 500 600 1000
Cost 1200 1500 1600
```

I want to be able to project these figures 10 years into the future, based off a straight line average of the previous years (i.e each year units would increase by 133 and cost by 166). What is the best way to do this within the constructs of pivot tables (never used them before)

Here's a few options ive considered:

**Calculate growth in the field table**: Not sure how to do this, my current attempts mean that 2012 is a duplicate column next to each of the previous years**Create a separate sheet for calculations:**Copy the data from the pivot table into a sheet, calculate the growth figures, normalise them into the same table as the raw data, then update the pivot table (as you can see, im trying to avoid this option).

So essentially my issues are where and how is it best to calculate the growth. Have googled the topic to surprisingly little yield. Any help vastly appreciated!

beforepivotting them - so it is easier to see what is going on and you have the flexibility to change the growth projections by any amount for any year and any metric. I would rearrange the source so each year is a different column and use a formula (with +133 or +166) to fill in 2012 and subsequent years. – pnuts Dec 1 '12 at 10:45