That's quite a lot! One of every 25, so probably at least one on the front page at any time? Are there domains that account for considerably more than 4%? Would be interesting to see a top ten list.
Top 10 domains by # of items on front page since 1/1/18:
rank | domain | count
------+-----------------+-------
1 | github.com | 2041
2 | ycombinator.com | 1911
3 | nytimes.com | 1818
4 | bloomberg.com | 1028
5 | medium.com | 826
6 | techcrunch.com | 735
7 | theguardian.com | 666
8 | github.io | 615
9 | bbc.com | 558
10 | arstechnica.com | 493