You have been in this stock longer than I am so I

You have been in this stock longer than I am so I suppose that you can recall if there were acquisitions in the first two - three months of 2013? If so, most likely these deals were closed with xx restricted shares, and since the legend can be removed after a year they become free trading. Counterparties usually don't wait but try to cash in asap, and that might also help explain the flooding of shares.