condition mean min max ZT0-3 12.975774999999999 11.655 14.29655 ZT4-7 14.22815 14.22815 14.22815 ZT8-11 22.52805 22.52805 22.52805 ZT12-15 0 0 0 ZT16-19 22.87605 22.87605 22.87605 ZT20-23 20.3476 20.3476 20.3476