How soon can I file for PERM while on H1b

Can I start my Perm on my 4th year on H1b? under EB3 Category ? I believe as of now priority date for Mexico EB3 if 2010. Does that mean that if I apply today it “ might “ take “ around “ 3 – 4 years to be able to file my I-485 ? Thank you!! Love this blog.