condition mean min max ZT0-3 3.28892 3.28892 3.28892 ZT4-7 0.376154 0.376154 0.376154 ZT8-11 2.208075 2.208075 2.208075 ZT12-15 4.48995 4.48995 4.48995 ZT16-19 6.927945 6.927945 6.927945 ZT20-23 5.915845 5.915845 5.915845