condition mean min max ZT0-3 21.25 21.25 21.25 ZT4-7 6.4 6.4 6.4 ZT8-11 44.650000000000006 44.650000000000006 44.650000000000006 ZT12-15 9.55 9.55 9.55 ZT16-19 19.599999999999998 19.599999999999998 19.599999999999998 ZT20-23 20.450000000000003 20.450000000000003 20.450000000000003