condition mean min max ZT0-3 11.541205 9.39546 13.68695 ZT4-7 14.35145 14.35145 14.35145 ZT8-11 12.4255 12.4255 12.4255 ZT12-15 0 0 0 ZT16-19 19.7607 19.7607 19.7607 ZT20-23 15.103 15.103 15.103