condition mean min max ZT0-3 7.9376999999999995 7.3396799999999995 8.53572 ZT4-7 7.98566 7.98566 7.98566 ZT8-11 10.430995 10.430995 10.430995 ZT12-15 0 0 0 ZT16-19 11.37795 11.37795 11.37795 ZT20-23 9.057515 9.057515 9.057515