Keala, the Civil Beat article is correct.  That 60,757 number of firearms is the number bought in one year.  The 21,544 permits is also for one year, 2013.  With one permit, you can buy more than one long gun.

Later in the same article: "Permits can be used to acquire an unlimited number of rifles and shotguns, but in most counties – Hawaii County included — each handgun requires an individual permit."

"Since the state began tallying such statistics in 2000, more than 180,000 firearms have been registered statewide some more than once."

"But the state didn’t began requiring registration until 1994, and while it is unknown how many firearms have left the state, it was estimated in the late 1990s that there were at least 1 million guns in Hawaii, which currently has a population of 1.4 million."

Also:  http://ag.hawaii.gov/cpja/files/2017/05/Firearm-Registrations-in-Hawaii-2016.pdf