condition mean min max ZT0-3 3.506913833333333 0.5471915 5.267415 ZT4-7 0.6701575 0.6701575 0.6701575 ZT8-11 2.10949 2.10949 2.10949 ZT12-15 2.3037875 1.4505249999999998 3.15705 ZT16-19 4.2493 4.2493 4.2493 ZT20-23 7.267835 7.267835 7.267835