condition mean min max ZT0-3 0.518879 0.36573350000000004 0.737491 ZT4-7 0.160933 0.160933 0.160933 ZT8-11 1.8882599999999998 1.8882599999999998 1.8882599999999998 ZT12-15 1.53598725 1.0270044999999999 2.04497 ZT16-19 0.5675545 0.5675545 0.5675545 ZT20-23 0.6750625 0.6750625 0.6750625