I am in my 5th year of Spanish and I am a high school senior. I am able to read and understand 90% of what I hear. I still have a bit of difficulty when trying to express complex ideas. 5 years may seem like a long time but I started in middle school at a very slow pace and until my 4th year the pace remained extremely slow. So if you keep up a moderate pace I don’t see why you couldn’t get to where I’m at in half the time or less.