condition mean min max ZT0-3 7.1171516666666665 6.42043 7.66638 ZT4-7 9.22787 9.22787 9.22787 ZT8-11 4.78172 4.78172 4.78172 ZT12-15 4.8690750000000005 4.152895 5.585255 ZT16-19 6.4639500000000005 6.4639500000000005 6.4639500000000005 ZT20-23 6.10998 6.10998 6.10998