condition mean min max ZT0-3 15.043904 15.043904 15.043904 ZT4-7 14.990938499999999 14.990938499999999 14.990938499999999 ZT8-11 18.664489 18.664489 18.664489 ZT12-15 18.407125999999998 18.407125999999998 18.407125999999998 ZT16-19 18.570644 18.570644 18.570644 ZT20-23 24.3864375 24.3864375 24.3864375