There's your answer - 0.2pp is totally insubstantial, which makes the title borderline clickbait. The economy doesn't uniformly grow or distribute wealth, so a change so small could just be from the distribution of college leavers in a particular year being overindexed towards sectors that aren't growing.
Further to that point, it typically takes years for people to adjust their majors towards sectors of the economy that are particularly productive, so we shouldn't expect to see such a quick change in the numbers.