condition mean min max ZT0-3 30.407775 26.9601 33.855450000000005 ZT4-7 28.4488 28.4488 28.4488 ZT8-11 46.343050000000005 46.343050000000005 46.343050000000005 ZT12-15 0 0 0 ZT16-19 51.7451 51.7451 51.7451 ZT20-23 42.29265 42.29265 42.29265