condition mean min max ZT0-3 23.323005 23.323005 23.323005 ZT4-7 17.3597915 17.3597915 17.3597915 ZT8-11 18.1983115 18.1983115 18.1983115 ZT12-15 17.3313985 17.3313985 17.3313985 ZT16-19 21.443733 21.443733 21.443733 ZT20-23 18.1388 18.1388 18.1388