condition mean min max ZT0-3 2.2231031666666667 1.0335395 4.274565 ZT4-7 0.402134 0.402134 0.402134 ZT8-11 0.41932050000000004 0.41932050000000004 0.41932050000000004 ZT12-15 0.6894855 0.5949935000000001 0.7839775 ZT16-19 0.6381405 0.6381405 0.6381405 ZT20-23 1.259765 1.259765 1.259765