condition mean min max ZT0-3 26.049999999999997 26.049999999999997 26.049999999999997 ZT4-7 9.1 9.1 9.1 ZT8-11 28.4 28.4 28.4 ZT12-15 28.950000000000003 28.950000000000003 28.950000000000003 ZT16-19 10.6 10.6 10.6 ZT20-23 14.899999999999999 14.899999999999999 14.899999999999999