condition mean min max ZT0-3 3.68322 1.6706050000000001 5.316875 ZT4-7 1.7029800000000002 1.7029800000000002 1.7029800000000002 ZT8-11 2.83516 2.83516 2.83516 ZT12-15 6.8094149999999996 3.674005 9.944825 ZT16-19 9.115075 9.115075 9.115075 ZT20-23 8.61323 8.61323 8.61323