Sportscaster Cards and PSA - Almost a Year Later

In January of this year there were just over 5,100 Sportscaster cards graded by PSA.  Today that number is up to 5,662.  I had nothing to do with that since I've never sent a card of any kind to PSA.  I own a few PSA cards, mostly Kellogg's, but it isn't something I chase.

Are any of you submitted these cards?  Other than the top few cards in the set, what is your reason for this?

64 125 59

In January there were the following totals -

Larry Bird                 57
Wayne Gretzky       119
Magic Johnson         53

today

Larry Bird                64    --- added seven this year
Wayne Gretzky      125    --- added six this year
Magic Johnson        59    --- added six this year

These three certainly didn't help much with the increase of over 500 submitted cards. 

I don't follow player master sets but is this what is happening?