condition mean min max ZT0-3 20.5719 16.8902 23.46545 ZT4-7 19.39815 19.39815 19.39815 ZT8-11 19.5396 19.5396 19.5396 ZT12-15 30.441850000000002 28.88975 31.99395 ZT16-19 30.651249999999997 30.651249999999997 30.651249999999997 ZT20-23 32.855 32.855 32.855