condition mean min max ZT0-3 680.645982 680.645982 680.645982 ZT4-7 662.9086494999999 662.9086494999999 662.9086494999999 ZT8-11 754.6321825 754.6321825 754.6321825 ZT12-15 818.065171 818.065171 818.065171 ZT16-19 857.5820775 857.5820775 857.5820775 ZT20-23 1040.8234 1040.8234 1040.8234