How many staff does Riot have?

I know this was a post back in 2010 (I looked it up, http://forums.na.leagueoflegends.com/board/showthread.php?t=260694&page=2 ) But how many staff does Riot have? A Rioter reply would be helpful. I use this as a constant point in my conversations when people rage about how they never get Riot replies. http://boards.na.leagueoflegends.com/en/c/miscellaneous/wKqHqEnl-riot-please-at-least-pretend