Unless you specify otherwise, match utility labels print continuously.  This means the most logical number to print per-shooter is 6 or 15; otherwise, you'd have a shooter's labels straddling pages.

Now there's the option to print blank labels at the bottom of the page.  This mostly makes sense if you want 9 or 12 labels per shooter.

In the example illustrated, three shooters' labels will print on each page (27 labels).  Then the system will leave one blank row of 3 labels and start the next shooter on the next page.