When does jailbreak come out for each iOS update usually?

I've finally decided to jailbreak my iPhone 4 after pondering it over a bit, and it's my first time.
I've already synced it, and backed it up to iCloud, but it seems as if the version for the most recent iOS update for iPhone 4 hasn't come out yet.
When does a new version usually come out? How long does it normally take?

Jailbreakers find flaws in iOS that allows them to gain access to the lower levels of the system that can't normally be reached. As these flaws are fixed it becomes increasingly hard to jailbreak the system. There are no known jailbreaks for the current version of iOS (6.1.3) and it will not known until they are available if there will be jailbreaks for future updates.

Ordinarily there's no good reason to jailbreak an iOS device - unless you are 12 and think you are magically going to get everything for free or you have some specific need to access the system at a lower level.