condition mean min max ZT0-3 7.119905 7.119905 7.119905 ZT4-7 3.164235 3.164235 3.164235 ZT8-11 18.076 18.076 18.076 ZT12-15 38.7174 38.7174 38.7174 ZT16-19 23.994 23.994 23.994 ZT20-23 13.245999999999999 13.245999999999999 13.245999999999999