condition mean min max ZT0-3 19.355716666666666 16.548499999999997 23.36785 ZT4-7 19.08445 19.08445 19.08445 ZT8-11 25.391550000000002 25.391550000000002 25.391550000000002 ZT12-15 28.5213 28.3825 28.6601 ZT16-19 23.87315 23.87315 23.87315 ZT20-23 27.0596 27.0596 27.0596