condition mean min max ZT0-3 12.161478333333333 10.124535 15.35075 ZT4-7 5.499855 5.499855 5.499855 ZT8-11 2.09161 2.09161 2.09161 ZT12-15 1.51461925 1.0267184999999999 2.00252 ZT16-19 0.8752675000000001 0.8752675000000001 0.8752675000000001 ZT20-23 2.3484 2.3484 2.3484