condition mean min max ZT0-3 14.350000000000001 14.350000000000001 14.350000000000001 ZT4-7 16.2 16.2 16.2 ZT8-11 31.0 31.0 31.0 ZT12-15 2.8499999999999996 2.8499999999999996 2.8499999999999996 ZT16-19 6.15 6.15 6.15 ZT20-23 19.25 19.25 19.25