condition mean min max ZT0-3 6.227088729250001 5.7366098475000005 6.717567611000001 ZT4-7 6.528637854 6.1850372815 6.872238426500001 ZT8-11 4.126782382 3.8172094430000003 4.436355321000001 ZT12-15 4.46409311575 3.824964307 5.1032219245 ZT16-19 8.11978543275 5.801765101499999 10.437805764 ZT20-23 12.686826795 11.779678715 13.593974875