Your chances of getting a show on the air at a major broadcast network are at about 6%.
To put that in perspective:
You have a better shot at getting cancer (14%)
Heart disease (20%)
And getting laid by a hipster in Silver Lake if your opening line involves quoting Kafka (100% if you bring your own PBR, 95% all other drafts)
Last year, ABC comedy bought 74 scripts and only 5 will air at some point this year. NBC comedy wasn't far off, with only 5 shows out of 79 scripts. Fox has 5 new comedy series out of 65, and CBS has only 4 out of 52, which isn't as bad until you remember that they probably spend all of their money on bodyguards to protect Chuck Lorre from Charlie Sheen.
The dramas don't tell a much better tale; your chance of getting a show on the air hovers around 8%. And this only happened if you know the right people to get you in the room to sell a script, and assuming you don't get saddled with network and studio executives who like to use phrases like "activate the essence of her neuroses earlier" that aren't phrases so much as words strung together in the hope that you'll get so disoriented you won't realize their notes aren't really notes, and you make it to the pilot round of the party - where your first episode is shot and then aired Hunger Games style for tourists who were too lazy to wait in line for the Simpsons ride at Universal Studios to vote on whether your lead character was outperformed by his monkey sidekick (spoiler alert: he was).
Guess that day job isn't looking so bad, is it?