condition mean min max ZT0-3 9.141178333333333 4.81978 11.3378 ZT4-7 4.812525 4.812525 4.812525 ZT8-11 4.6621950000000005 4.6621950000000005 4.6621950000000005 ZT12-15 6.469455 5.300715 7.638195 ZT16-19 7.66235 7.66235 7.66235 ZT20-23 11.2323 11.2323 11.2323