Pitching AFTER Perfect Games

I received a question from one of the hosts of a Chicago sports talk station (WSCR, 670 AM), who asked if the game that Philip Humber AFTER he had pitched his perfect game on April 21st, 2012 was the worst game after. Since there have only been 21 perfect games played, it was an easy one to research, and here's the data:

Box score data doesn't exist for the first four perfect games, reducing our sample size to 17 games. My primary unit of measure is the Game Score (GSc), a metric developed by Bill James to determine the effectiveness of a starting pitcher. The measure starts at 50 and adds:
1 point for each out, 3 for each complete inning, 2 for each inning after the 4th and 1 for each strikeout
It subtracts:
-2 for each hit, -4 for each earned run, -2 for each unearned run and -1 for each walk

I strongly suggest magnifying the browser to see the numbers, but it would appear that Humber's next outing after his perfect game WAS the worst follow-up game after a perfect game. He gave up 9 runs in 5 innings, and the next-closest would be Catfish Hunter's follow-up in 1968. In two examples, I had to look at games in the next season, but the numbers show what has been known for as long as baseball has been played--one game's results have no bearings on the next.