condition mean min max ZT0-3 1.0469373333333334 0.700957 1.30657 ZT4-7 1.087695 1.087695 1.087695 ZT8-11 1.22113 1.22113 1.22113 ZT12-15 1.6843849999999998 1.6736849999999999 1.695085 ZT16-19 1.771575 1.771575 1.771575 ZT20-23 1.193605 1.193605 1.193605