Sample size isn't big enough at either table amount although in both samples you know you are a winner with nearly 100% confidence.

But anyway obviously there is a direct correlation between number of tables and winrate. I have no clue why you would want to play 16 tables at 25NL anyway. It stunts your growth really early on. Maybe grind a few hours a week 16 tabling if you feel it gives you a slightly higher hourly or you have some VPP roles but otherwise I would stick to low # of tables and try to move up.

Also if you are playing only 6-8 tables you can focus a little more on looking for softs spots at 50NL if you are nearly rolled but don't want to sit in 8 games right away.