condition mean min max ZT0-3 12.934007695 11.30400676 14.56400863 ZT4-7 8.262145462500001 7.927344559 8.596946366000001 ZT8-11 10.176821254250001 7.3881178265 12.965524682 ZT12-15 15.630284097499999 15.412910265 15.847657929999999 ZT16-19 18.2579658075 18.10663257 18.409299045 ZT20-23 16.914463507500002 16.762172145 17.06675487