condition mean min max ZT0-3 1.7 1.7 1.7 ZT4-7 1.5 1.5 1.5 ZT8-11 14.5 14.5 14.5 ZT12-15 2.85 2.85 2.85 ZT16-19 2.8499999999999996 2.8499999999999996 2.8499999999999996 ZT20-23 3.5500000000000003 3.5500000000000003 3.5500000000000003