I have provided this link to Slash Key (the game developer) for you the Farmer.
This information was provided by S/K the game developers on 13 March 2015 from their new release updates.
The FarmCash activity log will show data from the last 6 months. Tracking started at the beginning of March 2015  so you will see no data before March.
FarmCash Activity Log section in the Account tab that will show every single transaction that involves farm cash or farm cash items, this way it will be very easy for anyone to answer the question 'Where did my Farm Cash go?'. It will show your farm cash purchases with real money (with links to Facebook receipts), trial pay offers completed, farm cash earn via quests, levels or gift certificates you have received.
It will also show all the farm cash items that you have purchased, sent as gift, deleted or sold. And finally there is a link on the top right that will link to a Facebook page that will show all your purchases inside any Facebook application, not just Farmtown.