condition mean min max ZT0-3 2.566676419 0.5989297 4.534423138 ZT4-7 0.7508986089999999 0.22665414749999999 1.2751430705 ZT8-11 8.4743725575 6.25437348 10.694371635 ZT12-15 8.57967498 7.848757417 9.310592543 ZT16-19 3.0457411925 2.3047826760000003 3.7866997089999996 ZT20-23 1.0298971527499998 0.8241704944999999 1.235623811