condition mean min max ZT0-3 15.056901 15.056901 15.056901 ZT4-7 15.2076625 15.2076625 15.2076625 ZT8-11 13.316662 13.316662 13.316662 ZT12-15 19.3208325 19.3208325 19.3208325 ZT16-19 16.3135665 16.3135665 16.3135665 ZT20-23 13.055420999999999 13.055420999999999 13.055420999999999