condition mean min max ZT0-3 2.3767204105 2.238428609 2.5150122120000002 ZT4-7 6.61367890975 6.095724409000001 7.131633410499999 ZT8-11 18.2259525115 12.024085097999999 24.427819925 ZT12-15 23.493623657500002 23.08336827 23.903879045 ZT16-19 15.795278362500001 14.549038915 17.041517810000002 ZT20-23 14.7535436725 13.917372494999999 15.58971485