Core 2 Stepping Timeline

As the title suggests how long into Core 2's lifespan did they start coming out with revisions/different steppings? Do all steppings follow a similiar timeline (ex. every 6-8 months or so, throughout lifespan). How long into Core 2's lifespan was E0 released?

Thanks in advance.

I think it was around 2 years .

First the e6300/E6400/E6600's came out Then the E6320/E6420
Then the E6550/E6750 ish stuff Then the E5xxx and the E2xxx
Then the 45nm stuff then the e0's

So far Intel has come out w/ a chip and then a new stepping about 6 months later. There is typically only 1 new stepping, though, before Intel moves on to a completely new chip design.

The new stepping is like an intermediate before the next tick or tock occurs.