condition mean min max ZT0-3 1.498345 1.498345 1.498345 ZT4-7 1.301285 1.301285 1.301285 ZT8-11 2.54955 2.54955 2.54955 ZT12-15 3.3630050000000002 3.3630050000000002 3.3630050000000002 ZT16-19 2.107875 2.107875 2.107875 ZT20-23 1.83079 1.83079 1.83079