I'm trying to add a field called "change date" which I indicated in the table. I have the table already with the other three columns. It is shown below but I want to get the date of the last change for each contract. Would this involve some kind of loop? I am not sure where to start here. The dates are just examples, it could be anywhere from 2007 to current. Thanks for the help.

```
Date Contract Status Change Date
9/30/2015 1 A 6/30/2015
8/31/2015 1 A 6/30/2015
7/31/2015 1 A 6/30/2015
6/30/2015 1 A 6/30/2015
9/30/2015 2 D 8/31/2015
8/31/2015 2 D 8/31/2015
7/31/2015 2 A 6/30/2015
6/30/2015 2 A 6/30/2015
9/30/2015 3 D 9/30/2015
8/31/2015 3 E 8/31/2015
7/31/2015 3 A 6/30/2015
6/30/2015 3 A 6/30/2015

```