求助：刚拿到PERM,EB3申请Green Card还要多长时间？

It has been 3 years since I began to apply for Green Card. I was almost dissapointed and don't want to work in the company any more. I am going to quit the job and find another way to stay in the States and set up my own business. But beyond my expecation, the perm was approved a couple of days ago, so it makes me difficult to decide keeping or quitting the job now. How many years do I have to wait to get the Card through EB3 application?