What countries have the most billion-dollar startup companies per capita?

What countries have the most unicorns (i.e., billion-dollar startup companies) per capita (i.e., per person)?

Oddly, I couldn’t find this anywhere, so I calculated it.

The winners:

1. Singapore
2. Israel
3. the United States
4. Estonia
5. Ireland

Here’s the full chart I created:

Interestingly, the top of the table pretty closely follows the amount of startup investment per capita according to this chart from Crunchbase: