Students with Norwegian as a mother tongue in primary schools to become a minority in Oslo by 2021

In 2000, 31% of students in primary schools in Oslo had languages other than Norwegian as a mother tongue, and this has since become 40%; at this rate students with Norwegian as a mother tongue will become a minority by 2021. This article here has an interactive image where you can see the ratio of minority groups (Minoritets-språklige elever) in Oslo from 2006 to 2010, and for an article in simple Norwegian (including a robotic voice reading the article if you like by pushing the Opplesing button on the top) about the same subject see here.

What this means in actual numbers can be seen here - at the moment there are 53120 students in primary schools in Oslo, and 21051 of them speak a minority language. The total number of minority languages here is 150, so hardly a monolithic group. Of this, 12704 are receiving training in Norwegian. The way this works is as follows:

-Students who aren't quite proficient in the language but can follow along receive special instruction to improve at Norwegian, and
-Students who aren't yet good enough at the language to even follow along have the right to education in their mother tongue.

So the important number here probably isn't simply the number of students who have a different language as a mother tongue, but rather the percentage of those that are able to follow along in Norwegian vs. those who are so bad at the language that they need to learn in another language, and how to quickly move students from the latter category to the former. If the language is taught well enough to students from a minority background, Norwegian will actually benefit since every one of these then becomes one more speaker of the language. So another way to phrase the situation instead of "minority-language students to become majority by 2021" would be something more along the lines of "Norwegian to increase number of new speakers in primary schools from 12000 to (about?) 20000". Since the population of the entire country is still only about 4.9 million, that's actually quite a large increase.

And besides, even tiny Latvia has been able to increase the percentage of those learning in Latvian from 60.3% in 1995 to 73% 11 years later.