condition mean min max ZT0-3 8.889457499999999 8.156535 9.62238 ZT4-7 5.5746 5.5746 5.5746 ZT8-11 5.75789 5.75789 5.75789 ZT12-15 0 0 0 ZT16-19 7.74358 7.74358 7.74358 ZT20-23 6.937475 6.937475 6.937475