Okay, so you aren't actually talking about the immigration rate, you're talking about the percent of people who are immigrants. That has nothing to do with the "pace of the last 10 years", it comes down to the pace of the last 50 years, coupled with the selection of people you happen to see around you. And taking a break for 20 years will still leave all of those foreign-born people here, unless that was (too subtly for me) suggesting the immigrants already here leave.

And who's to say that a country can't sustain a high foreign-born population without authoritarianism? Germany's is even higher, and the US maintained a comparable level for 70 years in the 1800s. That seems like a wild claim.