condition mean min max ZT0-3 13.0129 13.0129 13.0129 ZT4-7 7.748175 7.748175 7.748175 ZT8-11 7.7404150000000005 7.7404150000000005 7.7404150000000005 ZT12-15 12.8629 12.8629 12.8629 ZT16-19 16.3166 16.3166 16.3166 ZT20-23 15.1827 15.1827 15.1827