New data out of Germany using serological testing found 14 % of the population presented antigens against COVID19. This is massive if nearly 1/7 of the population has already contracted the disease and developed some type of immunity. This is only one piece of data, however, and is even much higher than the Iceland estimates of 50% asymptomatic and 50% symptomatic.
German study
Iceland information
https://www.cnn.com/2020/04/01/europe/iceland-testing-coronavirus-intl/index.html
Shameless self promotion, but I did recently launch a blog with high level links and commentary due to the lockdown. Feel free to delete if this isn't the place for this.
https://www.palisatrium.com/