condition mean min max ZT0-3 25.846836 25.846836 25.846836 ZT4-7 25.1972425 25.1972425 25.1972425 ZT8-11 22.255522499999998 22.255522499999998 22.255522499999998 ZT12-15 21.108921 21.108921 21.108921 ZT16-19 23.8838975 23.8838975 23.8838975 ZT20-23 20.735502 20.735502 20.735502