So, following the smackdown I received, I went and ran some numbers. This is the proportion of people aged 90 or more at the time they appeared on the list over the past decade.
2019 - 60%
2018 - 62%
2017 - 58%
2016 - 56%
2015 - 64%
2014 - 62%
2013 - 62%
2012 - 52%
2011 - 56%
2010 - 50%
I'd call that inconclusive, although clearly my perception was wrong. 2019 certainly is right in the middle of the range of the past few years, but one could make the case for creeping inflation since 2010.
Interestingly, 2012 was the last year that none of the top 5 was aged over 86 and we lost the entire top 3 that year.