condition mean min max ZT0-3 2.6064521666666662 1.5388165 3.3309499999999996 ZT4-7 1.313775 1.313775 1.313775 ZT8-11 3.210845 3.210845 3.210845 ZT12-15 3.4187650000000005 2.315205 4.522325 ZT16-19 4.462375 4.462375 4.462375 ZT20-23 3.904305 3.904305 3.904305