condition mean min max ZT0-3 8.162953333333332 5.462885 13.32125 ZT4-7 9.842775 9.842775 9.842775 ZT8-11 4.05471 4.05471 4.05471 ZT12-15 6.40883 5.8988499999999995 6.91881 ZT16-19 4.135625 4.135625 4.135625 ZT20-23 5.281499999999999 5.281499999999999 5.281499999999999