In the pre-vaccination era in Sweden, smallpox was estimated to have been responsible for 2,000 deaths per million people every year; in other terms, this meant that approximately 0.2 percent of the entire population (or one in every 500 people) would die of smallpox annually. From looking at other data sets, we know that this figure was as high as 7,200 deaths per million in some years, as individual epidemics regularly devastated large portions of the population. When Jenner's findings on vaccination were adopted by the scientific community in Europe, Sweden was one of the first countries to begin vaccinating infants on a large scale. This is reflected in the considerable decline of smallpox deaths in the early nineteenth century, where the number of deaths fell to just 623 annual smallpox deaths per million in the first decade. By the middle of the century, when vaccination was made compulsory by the Swedish government, it dropped even further, to less than ten percent of the pre-vaccination death rate. In the last two decades in the nineteenth century, when Swedish authorities began penalizing parents for not vaccinating their children, the smallpox death rate fell to just two deaths per million people, and Sweden reported its final endemic (naturally occurring) case of smallpox in 1895; making it the second country in the world (after Iceland in 1872) to successfully eradicate the disease.

Smallpox is an acute contagious disease caused by the variola virus, a member of the orthopoxvirus family. It was one of the most devastating diseases known to humanity and caused millions of deaths before it was eradicated. It is believed to have existed for at least 3000 years.

@article{owidsmallpox, author = {Sophie Ochmann and Max Roser}, title = {Smallpox}, journal = {Our World in Data}, year = {2018}, note = {https://ourworldindata.org/smallpox} }

From the original source. So If you use the data here pls cite them thanks :)

Error bars on the Costantino et. al. values are a 95% confidence interval.