condition mean min max ZT0-3 7.6125549999999995 7.16025 8.372245 ZT4-7 3.121525 3.121525 3.121525 ZT8-11 1.4935800000000001 1.4935800000000001 1.4935800000000001 ZT12-15 0.87866175 0.715442 1.0418815 ZT16-19 1.817155 1.817155 1.817155 ZT20-23 4.116275 4.116275 4.116275