condition mean min max ZT0-3 17.833775 15.6111 20.056449999999998 ZT4-7 13.1881 13.1881 13.1881 ZT8-11 9.507395 9.507395 9.507395 ZT12-15 0 0 0 ZT16-19 10.947635 10.947635 10.947635 ZT20-23 15.803650000000001 15.803650000000001 15.803650000000001