condition mean min max ZT0-3 6.616895 4.645945 10.268785000000001 ZT4-7 8.49992 8.49992 8.49992 ZT8-11 4.838884999999999 4.838884999999999 4.838884999999999 ZT12-15 5.0379825 4.324705 5.75126 ZT16-19 3.50353 3.50353 3.50353 ZT20-23 5.37806 5.37806 5.37806