condition mean min max ZT0-3 3.7183275 3.19666 4.239995 ZT4-7 1.8266499999999999 1.8266499999999999 1.8266499999999999 ZT8-11 1.5928149999999999 1.5928149999999999 1.5928149999999999 ZT12-15 0 0 0 ZT16-19 2.8996899999999997 2.8996899999999997 2.8996899999999997 ZT20-23 3.1033799999999996 3.1033799999999996 3.1033799999999996