condition mean min max ZT0-3 3.303173333333333 1.833425 4.45576 ZT4-7 2.39801 2.39801 2.39801 ZT8-11 3.22261 3.22261 3.22261 ZT12-15 3.9025775 3.39281 4.412345 ZT16-19 3.019375 3.019375 3.019375 ZT20-23 4.959995 4.959995 4.959995