The sample size would be the number of doctors in Canada. What is that number?
“The sample size would be the number of doctors in Canada.”
Well, partially. You also need, since you are comparing data from one time period to another, to have a large enough sample over time to make the comparison. We do not have that, since we only have data from one full year, compared to one partial year, and no previous year’s data to determine if even the full year’s data we have is a representative sample to begin with.