condition mean min max ZT0-3 6.332982062999999 6.281189218 6.384774908 ZT4-7 9.829674118749999 8.236399472999999 11.4229487645 ZT8-11 16.41844254 15.06976315 17.767121930000002 ZT12-15 8.320183879 6.593018692999999 10.047349065 ZT16-19 3.27649274275 3.1355527975 3.417432688 ZT20-23 1.9059297297500002 1.3092025285000002 2.502656931