condition mean min max ZT0-3 18.303075 17.62125 18.9849 ZT4-7 13.185849999999999 13.185849999999999 13.185849999999999 ZT8-11 11.1493 11.1493 11.1493 ZT12-15 0 0 0 ZT16-19 15.6297 15.6297 15.6297 ZT20-23 15.9791 15.9791 15.9791