condition mean min max ZT0-3 736.739782 736.739782 736.739782 ZT4-7 820.500142 820.500142 820.500142 ZT8-11 931.116887 931.116887 931.116887 ZT12-15 984.800066 984.800066 984.800066 ZT16-19 974.0759555 974.0759555 974.0759555 ZT20-23 958.3616705 958.3616705 958.3616705