condition mean min max ZT0-3 7.376211666666667 2.2504750000000002 11.6173 ZT4-7 0.8800335 0.8800335 0.8800335 ZT8-11 1.3048950000000001 1.3048950000000001 1.3048950000000001 ZT12-15 12.621224999999999 9.82765 15.4148 ZT16-19 14.1726 14.1726 14.1726 ZT20-23 13.2096 13.2096 13.2096