The main reason for that is the cruel way that averages work in that when I have had a low day, say 15k, it is very hard to find the extra time on other days to pull the average back up.
And I had a few more low days this year thanks to the gradual reopening of cafes, pubs and theatres etc. that gave me other things to do in the evenings.
With the resurgence of the pandemic in the later part of the year I have been avoiding pubs etc again, despite the government letting them stay open for unfathomably reasons, and that has again let me walk more; a quick pint is half an hour or just over 3,000 steps.
