condition mean min max ZT0-3 6.4714849999999995 2.399045 9.748204999999999 ZT4-7 2.216215 2.216215 2.216215 ZT8-11 3.1834499999999997 3.1834499999999997 3.1834499999999997 ZT12-15 4.721674999999999 3.8204599999999997 5.62289 ZT16-19 7.829865 7.829865 7.829865 ZT20-23 11.74225 11.74225 11.74225