According to Wikipedia (which cites U.S. Census data and CDC data, so I'm going with wikipedia anyway, for the sake of its easy-to-digest chart), the U.S. population has grown by well over 1,000,000 every year (not counting immigration) and some times more than twice that, every year since at least 1950.
I'm also looking at the U.S. immigration data found here (link from Wikipedia), for which 2010 is the last year available.
Now, I'm making a few assumptions:
Everyone enters the workforce at the age of 20, and works until they die.
Everyone enters the workforce before they die.
All legal U.S. immigrants enter the workforce.
These assumptions ought to lead to artificially high workforce figures for my following estimate, but should provide us with a useful upper-bound to weigh Mr. Limbaugh's claim against.
1992 had a natural population growth of 1,889,401, so this many new workers will be entering the workforce this year, given our assumptions.
In 2010, 1,042,626 legal immigrants came to the U.S. (We'll use the same number for 2012, since it's the latest data available).
This gives us 2,932,026 new workers in 2012.
So to maintian our current employment rate, we'd need to create, on average, 244,336 jobs every month.
I'd say Mr. Limbaugh was off by at least a factor of 2-3.
Unless, of course, he's pining for the rights of illegal immigrants who don't get counted in these numbers, and who cannot file for unemployment benefits. :)