[dredmorbius]

2 years: https://web.archive.org/web/20110709213326/https://blog.pinb...

3 years: https://web.archive.org/web/20120713030912/http://blog.pinbo...

4 years (broken HTML in the elevenversary post): https://blog.pinboard.in/2013/07/pinboard_is_four_years_old/

5 years (broken HTML in the elevenversary post): https://blog.pinboard.in/2014/07/pinboard_turns_five/

6--7 and 10 are valid.

Nine is apparently Right Out.

[huhtenberg]

> Nine

Something happened in 2018. There are no stats for that year too.

[wingerlang]

> Every year when I don't forget I try to publish the same stats

This implies he just forgot about it.