condition mean min max ZT0-3 3.8168550000000003 3.8168550000000003 3.8168550000000003 ZT4-7 2.2429300000000003 2.2429300000000003 2.2429300000000003 ZT8-11 6.33977 6.33977 6.33977 ZT12-15 10.575199999999999 10.575199999999999 10.575199999999999 ZT16-19 9.449539999999999 9.449539999999999 9.449539999999999 ZT20-23 5.01732 5.01732 5.01732