[mdp2021]

The 3% value (if I am reading data correctly) is because of the pandemic - the usual recent value would have been closer to (rounded) 10%, which received a blow in the 2020 frenzy; the "2019" study covers complete 2019 but includes 2020 data.

May I interest you in a past submission, https://news.ycombinator.com/item?id=31360319 , "Study finds the SARS-CoV-2 virus is not viable on cash banknotes".

About the special numbers of Sweden and Norway: this is what happens when living in Sweden and Norway, you get the false idea that reality is like Sweden and Norway look.