condition mean min max ZT0-3 12.304623333333334 10.07137 14.3968 ZT4-7 11.199665 11.199665 11.199665 ZT8-11 7.018925 7.018925 7.018925 ZT12-15 12.03145 11.947600000000001 12.1153 ZT16-19 7.877149999999999 7.877149999999999 7.877149999999999 ZT20-23 8.871585 8.871585 8.871585