condition mean min max ZT0-3 4.16427610275 3.717310585 4.6112416204999995 ZT4-7 6.0444714164999995 4.9864390929999995 7.1025037399999995 ZT8-11 7.9519451475 7.455430583 8.448459712 ZT12-15 12.10521368575 10.0925025015 14.11792487 ZT16-19 11.81601867 11.570067784999999 12.061969555000001 ZT20-23 11.991003229999999 11.850068109999999 12.131938349999999