condition mean min max ZT0-3 14.176475 13.37795 14.975 ZT4-7 15.6555 15.6555 15.6555 ZT8-11 15.6863 15.6863 15.6863 ZT12-15 0 0 0 ZT16-19 21.89975 21.89975 21.89975 ZT20-23 16.56575 16.56575 16.56575