condition mean min max ZT0-3 15.246791666666667 8.139975 19.4253 ZT4-7 10.682500000000001 10.682500000000001 10.682500000000001 ZT8-11 19.5611 19.5611 19.5611 ZT12-15 18.741275 14.6953 22.78725 ZT16-19 21.99895 21.99895 21.99895 ZT20-23 23.83265 23.83265 23.83265