See my table for testing rates by country here. The data is taken from Real clear politics but they have mistakenly used a population for Iceland of 5 Million (probably confused it with Ireland).

Using a corrected population figure of 0.364 Million, I have calculated the testing rate for Iceland as 79,646 tests per million inhabitants, which is, indeed, the highest rate in the world. Shows you the benefit of having a testing lab on your own doorstep and not being dependent on other countries for supplies.

Index of Frank's Diaries