I’m presenting historical data from the United States, because this is one of the places where we have reasonable long-term data on typhoid fever incidence.

This graph shows the annual incidence of typhoid fever in the United States from 1912 through 1994. During this 72-year period the incidence fell dramatically, from 82 cases to only 0.17 cases per 100,000 population, an almost 500 fold decline.