condition mean min max ZT0-3 6.265420000000001 6.110565 6.420275 ZT4-7 3.54697 3.54697 3.54697 ZT8-11 4.745115 4.745115 4.745115 ZT12-15 0 0 0 ZT16-19 7.86876 7.86876 7.86876 ZT20-23 7.525164999999999 7.525164999999999 7.525164999999999