I posted this for you a long time ago. Fitness Youtuber trained 8 weeks to go from 7:48 mile to 6:40 mile. He looks older than 20, so you'd expect less from him. He's starting from fitter than average as a fitness dude. And he gave himself twice the time to train. 7+/- minutes is probably a good answer for your question. You've run 6:50, so you are about average.