The most recent posting on this topic: on 3/5/19, “Another 100k spams”, where I noted that the number of spam comments here (since the blog started in December 2008) passed 5,600,000 on 3/3. Some were automatically deleted by WordPress software, a great many more were made available for bulk deletion (or individual inspection) by me, and some were submitted to me individually for moderation. In periodic spam attacks, comments spam arrives at the rate of more than one per second (until the software wrestles it to the ground again).
That was 3/3. On 7/23, the count passed 5,700,000. And then, yesterday (12/30), 5,800,000. 6 million beckons! (Probably not next year, but soon.)