Only way to get it back was if you used steam cloud, but I guess this isn't the case for you.
You stored your save files on your computer instead of steam cloud, which means they're sadly removed since you formatted your computer.
But hey man, you can download profiles if you want, but that is not what I really recommend to do, instead do this:
Create a new profile in-game and then use this program called TS SaveEditor Tool.
This will help you out, a lot.
Happy gaming!