Congratulations!!! 
I had to stop at N3 because I think I need to consolidate the acquired knowledge. I don’t have a ton of reviews on Bunpro, but I keep creating ghosts 
I also can’t really use most points in conversation and I keep forgetting a bunch of them when I’m reading/listening. So it may be 5 or 6 years for me 
But that’s okay. Keep it up, everyone!