condition mean min max ZT0-3 2554.246654 2554.246654 2554.246654 ZT4-7 2647.5055585 2647.5055585 2647.5055585 ZT8-11 2010.0720195 2010.0720195 2010.0720195 ZT12-15 2289.3568779999996 2289.3568779999996 2289.3568779999996 ZT16-19 1968.0820665 1968.0820665 1968.0820665 ZT20-23 1517.4650245 1517.4650245 1517.4650245