condition mean min max ZT0-3 26.82089886 23.06566939 30.576128330000003 ZT4-7 29.9690497 26.44251562 33.49558378 ZT8-11 22.771862555 20.43164475 25.11208036 ZT12-15 18.122433365 14.207658725000002 22.037208005 ZT16-19 22.0976952975 19.566782805 24.62860779 ZT20-23 30.535837275 29.438071295 31.633603254999997