Your graph is misleading because it only shows the data until the beginning of August.
Sweden has had restrictions on large gatherings in place the whole time. The Finnish and Swedish economies have contracted to a similar extent despite Finland having tighter restrictions in place in the spring. Much of the low rates of infection in the Nordic countries can be explained by the fact that the people normally behave as if they were in what is mandated by lockdowns in the south of Europe. People maintain a much larger distance between each other than in the south. There was little in the way of touching, kissing or anything like that even before Covid-19. Three-generation households are very rare. Single-person households are more common than anywhere else. There is no liberal use of antibiotics in animal husbandry like in the US or many of the southern European countries like Italy or Spain, which makes the risk of contracting a secondary bacterial pulmonary infection in addition to Covid-19 induced pneumonia much less of a risk. Air quality is much better than particularly Northern Italy.
I made this post on 16 Aug 2020 so my graph was quite up to date.
While I appreciate you looking at my older posts, its a bit strange commenting on a 3 months old post that its data is out of date. :-)
Damn, I didn't notice I was responding to an old post! Sorry about calling your graph out of date, mate.
The rest of my comment is still valid, though.