condition mean min max ZT0-3 1.33017 1.2042950000000001 1.496925 ZT4-7 1.1243349999999999 1.1243349999999999 1.1243349999999999 ZT8-11 1.44311 1.44311 1.44311 ZT12-15 2.2771575 2.127985 2.42633 ZT16-19 1.6192600000000001 1.6192600000000001 1.6192600000000001 ZT20-23 1.556745 1.556745 1.556745