It should be noted that there are hardly any Armenian Catholics in Armenia proper. There are very few in the whole world (wiki lists 700,000), and they, like the Orthodox counterparts from whom they came, are mostly outside of Armenia. I think the Armenian diaspora totals something like 8 million people, versus Armenia’s population of about 3 million. And something like 95% or more of Armenians are Orthodox, with the remainder being split between Catholics and various Protestants (shades of my recent post on the Copts, I guess…though the majority of the Copts remain in Egypt for now).
From what I’ve been able to find, it would not be unreasonable to expect more Catholics in Gymuri (Armenia’s second largest city) than in Yerevan, as Gymuri has a (the?) Armenian Catholic seminary. But even there the vast majority of the population is Orthodox. Armenia is not religiously or even terribly ethnically diverse. You’re basically either Armenian (Orthodox) or a Kurd (they’re the second largest ethnic group at a whopping 1.3% of the population, and they’re mostly Yazidi, not Muslim, from what I’ve been able to gather). The number of Catholics, like the number of Russians (Eastern Orthodox; 0.5%), or the number of Germans, is tiny.