condition mean min max ZT0-3 1.523287448 0.291585838 2.754989058 ZT4-7 0.8704818007499999 0.6613289754999999 1.079634626 ZT8-11 0.83206420725 0.446329152 1.2177992625 ZT12-15 2.1742944705 1.2123320345 3.1362569065 ZT16-19 5.93054891025 5.800485774 6.060612046499999 ZT20-23 7.09221759275 5.730135928 8.4542992575