Population size - country data from around the world:
The average for 2015 was 37.36 million.
The highest value was in China: 1371.22 million and the lowest value was in Tuvalu: 0.01 million.
Below is a chart for all countries where data are available for: Population size.
World bank definition: Total population is based on the de facto definition of population, which counts all residents regardless of legal status or citizenship. The values shown are midyear estimates.