condition mean min max ZT0-3 2.561645 2.561645 2.561645 ZT4-7 1.55993 1.55993 1.55993 ZT8-11 1.3475755 1.3475755 1.3475755 ZT12-15 1.32588 1.32588 1.32588 ZT16-19 2.58051 2.58051 2.58051 ZT20-23 2.94524 2.94524 2.94524