The US store is pretty much the only one where I get traction. Interestingly, my #2 is typically Australia, though it used to be UK. But the vast majority of my activity is in the US.
Mine too. UK second. Aus is third. But Aus is less than 5%.
But while I get the odd #1s from UK and Aus, I've not had a sniff of a #1 in the US all year. In fact, I think it's well over a year now. It's getting much harder to get there now.
What I find amazing though is, I got #10 in Space Opera in the US, and nothing higher than 9 in any other category. That's just bizarre! Normally I'd be getting #1 in Metaphysical, which this book wasn't even put into it seems, but be lucky to crack top 50 in Space Opera.
Whatever is going on in the US ranking system is having some strange effects. And yet, the UK seems unaffected.
As for my release speed, I guess I'm averaging about 2000 words a day at the moment, and hitting around the 65-70k mark for each book. Not overly fast by the standards of some.
The US population is certainly bigger. That doesn't mean that there are necessarily more self published authors. We don't have any accurate statistics on that. But I would assume the US has more, which might be a reason it's hard to get rankings in the US store in general. (This also assumes that US authors will do better in the US market, which isn't always true by any means. It would be so nice to have real statistics on some of these things.)
It has definitely become harder over time. I have hit #1 on some subgenres more than once, but not since about 2016 or 2017. The same number of sales that used to do it doesn't even come close. What little info I have suggests that new books are pouring in at a much higher rate.
Interestingly, it sounds as if we do roughly the same number of words per day. (I go for six pages, the "Stephen King" standard, which the way my drafts are laid, comes to about 1,900). But perhaps I have more days during which I don't make my goal for one reason or another. My current WIP looks as if it will hit around 170,000 words, which is actually shorter than my norm. That would suggest I should be cranking out a book once every 90-100 days if I'm working at the same pace as you, but that isn't what's happening.
By the way, my editor's turnaround is usually greater than the 35 days you have been books, which is also a factor. If I were writing shorter books, he would also be processing them faster. (My cover designer, meanwhile, has about a five-month backlog. I reserve when I'm about halfway through my first draft.)
Speaking of drafts, maybe you're a faster reviser than I am. It can take me quite a while.
