Unfortunately a fair bit longer - I'd say 6 years?
It took me a bit to catch on to the right approach and had to learn along the way (wasting time forever with a folks who were set on doing it their way into the ground and learning from clients doing a good job).
But what happened is once you focus on clients that work well with you (and you with them) then the reputation value just goes through the roof. It looks like everything you do "works" - but half of that is you are picking clients ready to make it work?
Now of course I have lots of different stress - you can grow too quickly - and even with staff can fall behind your clients now high standards - so a quick fall is possible. People paying premium $ expect a good result not unreasonably - especially if they themselves are delivering on a high level. No one minds if you screw up and are getting paid $25/hr. In some ways I miss those days. I def went out drinking a lot more back then.