Every day, the WHO releases a situation report on the novel coronavirus.
These reports include tables showing the number of cases by province in China/Taiwan (grouped together), as well as by country outside of China.
One interesting piece of information included in the tables is the likely place of exposure. For example, according to the the February 21 report, there are 1200 confirmed cases outside of China/Taiwan, with 175 due to likely exposure in China, 320 due to exposure in the reporting country, and 20 due to exposure outside of both. There are also 685 cases with origin under investigation. So, of cases with known origins, 175 / (1200-685) = 34% are due to exposure in China.
On March 27, of all confirmed cases outside of China and Taiwan, what will be the ratio (Due to likely exposure in China) / (Total confirmed - Under investigation)?
In earlier versions of the report, the "Due to likely exposure in China" column was instead labeled "Total cases with travel history to China". These mean roughly the same thing, so either one is acceptable.
If no WHO report with the specified information is published on March 27, we defer to the last such WHO report published before that date.