condition mean min max ZT0-3 15.536126666666666 7.63178 21.8812 ZT4-7 10.106 10.106 10.106 ZT8-11 11.21145 11.21145 11.21145 ZT12-15 11.904135 11.49582 12.31245 ZT16-19 18.95265 18.95265 18.95265 ZT20-23 28.765 28.765 28.765