condition mean min max ZT0-3 4.308015 2.5119350000000003 5.5943950000000005 ZT4-7 3.644375 3.644375 3.644375 ZT8-11 4.00262 4.00262 4.00262 ZT12-15 13.263572499999999 9.690695 16.83645 ZT16-19 15.158550000000002 15.158550000000002 15.158550000000002 ZT20-23 13.78185 13.78185 13.78185