11th out of 15 total, servicing about 4 flights / 630 passengers per day on average using the very same statistics you've linked. That sounds like a pretty small airport to me, both in absolute and relative terms.
"International airport" means very little outside of large nations like the US, Russia, Canada, Brazil or China. Most nations are small enough that there's at least as many foreign airports within a few hundred kilometers as there are domestic ones, and therefore every airport may as well be an international airport.
In the U. S., at least, "international" just means there's a customs station. There are some pretty small airports that have "international" in the name. Fairbanks, Alaska, comes to mind.
It's... a tiny airport, both by commercial standards and by South Korean standards.
Pretty sure you're just trolling though, no way this is a serious comment.