condition mean min max ZT0-3 1.5890469999999999 0.314769 3.1082349999999996 ZT4-7 3.371975 3.371975 3.371975 ZT8-11 1.7101595 1.7101595 1.7101595 ZT12-15 3.0163525 2.57986 3.452845 ZT16-19 1.4185249999999998 1.4185249999999998 1.4185249999999998 ZT20-23 0.48693699999999995 0.48693699999999995 0.48693699999999995