condition mean min max ZT0-3 16.024718 16.024718 16.024718 ZT4-7 15.422215000000001 15.422215000000001 15.422215000000001 ZT8-11 16.1821075 16.1821075 16.1821075 ZT12-15 27.007078 27.007078 27.007078 ZT16-19 18.345041 18.345041 18.345041 ZT20-23 17.438515000000002 17.438515000000002 17.438515000000002