I would say it is normal to a certain extend. Imagine in the past 6 years how many domains were registered vs how many new people gained internet access. I would expect visits to go a bit thinner as well as time spent on the site. Assuming the site holds a certain position.
However if you check the server logs - in case you keep them - you may notice the overall traffic is higher now. More bots looking for things and the ratio of human visitors/bots is way lower than it was 6 years ago.