iCarly season 4: Why do they take so long to air new episodes?

Ever since the show started, they would air a new episode every
Saturday. But in season 4, the first 5 episodes were aired every other
Saturday. Then they aired one 3 weeks later, then another one 3 months
later, and from there, there was only 1 new episode every month or
every other month.

Why aren't they airing them every week, like they used to?

I hate having to wait 1 month or more to see the next one.
JT: YOU suck!