Posts to e621 during October of each year: (expand me)
2007: 262
2008: 412
2009: 3.0k
2010: 3.4k
2011: 5.1k
2012: 7.0k
2013: 8.4k
2014: 9.0k
2015: 16.1k
2016: 20.5k
2017: 19.3k
2018: 21.3k
2019: 26.4k
2020: 34.7k
2021: 43.8k
2022: 57.8k
2023: 57.8k (should end up a little bit higher since 10-31-23 is ongoing)
I was going to pull the numbers from each year but it turns out e621 only returns about 53k results per search, and you'd have to start breaking searches in half to get the real number. This quickly got out of hand from 2010 onwards so October it is.
TLDR we are up, up, and away.