The thing of it is, Nickelodeon treats the show like crap, since it's not one of their IPs. Logistically speaking, the show should be already be airing Season 6 by now, but so far, they've only aired three Season 5 episodes, and have yet to air anymore - and they haven't for about 9 months. And this isn't even the first time they've done this: Season 3 went through multiple hiatuses that were several months long, which took two years for that entire season to finish airing; similarly, Season 4 also went through a prolonged mid-season hiatus as well, which is why we're so far behind in getting new episodes. Then again, you know how Nick is: if you're not SpongeBob or TLH, they couldn't care less.