condition mean min max ZT0-3 2.8499999999999996 2.8499999999999996 2.8499999999999996 ZT4-7 3.3 3.3 3.3 ZT8-11 13.9 13.9 13.9 ZT12-15 3.65 3.65 3.65 ZT16-19 3.2 3.2 3.2 ZT20-23 1.9500000000000002 1.9500000000000002 1.9500000000000002