condition mean min max ZT0-3 34.2 34.2 34.2 ZT4-7 4.3 4.3 4.3 ZT8-11 3.65 3.65 3.65 ZT12-15 15.5 15.5 15.5 ZT16-19 9.649999999999999 9.649999999999999 9.649999999999999 ZT20-23 7.300000000000001 7.300000000000001 7.300000000000001