I currently have a table that looks like this:

```
fscYear ID          Days    #Invoices     AVG
2011    20000807    221     7             27
2012    20000807    403     15            25
2013    20000807    390     14            26
2014    20000807    119     4             23

```

I would like to include the previous year's AVG in the next year, like so:

```
fscYear ID          Days    #Invoices   AVG  prevAVG
2011    20000807    221     7           27    0
2012    20000807    403     15          25    27
2013    20000807    390     14          26    25
2014    20000807    119     4           23    26

```

How I can achieve that?

*edit* the SQL is straightforward, 

```
select * from theTableThatHoldsThedata

```