condition mean min max ZT0-3 11.3 11.3 11.3 ZT4-7 5.0 5.0 5.0 ZT8-11 6.25 6.25 6.25 ZT12-15 31.549999999999997 31.549999999999997 31.549999999999997 ZT16-19 11.149999999999999 11.149999999999999 11.149999999999999 ZT20-23 4.3 4.3 4.3