condition mean min max ZT0-3 14.336007 14.336007 14.336007 ZT4-7 14.623705000000001 14.623705000000001 14.623705000000001 ZT8-11 11.521931 11.521931 11.521931 ZT12-15 13.050094999999999 13.050094999999999 13.050094999999999 ZT16-19 14.897389 14.897389 14.897389 ZT20-23 16.9861505 16.9861505 16.9861505