condition mean min max ZT0-3 2.4105091666666665 0.8718975 3.206405 ZT4-7 3.8873249999999997 3.8873249999999997 3.8873249999999997 ZT8-11 1.2437384999999999 1.2437384999999999 1.2437384999999999 ZT12-15 6.35189 5.31858 7.3852 ZT16-19 4.846685 4.846685 4.846685 ZT20-23 3.68605 3.68605 3.68605