condition mean min max ZT0-3 0.550650558 0.415573244 0.685727872 ZT4-7 1.10823750925 0.7434669145 1.473008104 ZT8-11 20.10876319775 8.4986189355 31.71890746 ZT12-15 40.357230920000006 40.127934710000005 40.58652713 ZT16-19 12.83897566725 8.741968926 16.9359824085 ZT20-23 4.82601825175 4.0505789585 5.601457545000001