condition mean min max ZT0-3 1914.5 1914.5 1914.5 ZT4-7 1887.5 1887.5 1887.5 ZT8-11 1922.0 1922.0 1922.0 ZT12-15 1769.85 1769.85 1769.85 ZT16-19 1684.9499999999998 1684.9499999999998 1684.9499999999998 ZT20-23 1999.3 1999.3 1999.3