I've been studying this year full time since very early May, have completed almost every lesson available with over 80% score (most I might miss 1), and have taken several PTs. I studied 2 years ago for about 5 hours/week, across a few months.
I'll be 23 when I enter law school (22 now), though was trying to enter back when I would have been 20. Ended up getting a couple good years of extra work experience, which has definitely helped with the LSAT.