condition mean min max ZT0-3 18.6 18.6 18.6 ZT4-7 24.2 24.2 24.2 ZT8-11 31.549999999999997 31.549999999999997 31.549999999999997 ZT12-15 17.450000000000003 17.450000000000003 17.450000000000003 ZT16-19 35.599999999999994 35.599999999999994 35.599999999999994 ZT20-23 21.549999999999997 21.549999999999997 21.549999999999997