Question: What were the causes of Brtain's population doubling every 50 years?
About the article "Industrial Revolution", section "Population increase".

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This article is about the demographic features of the population of Switzerland, including population density, ethnicity, education level, health of the populace, economic status, religious affiliations and other aspects of the population.
Switzerland has a population of 8.02 million as of 2012.
Its population has quadrupled over the period 1800 to 1990 (average doubling time 95 years).
Population growth was steepest in the period after World War II (1.4% per annum during 1950-1970, doubling time 50 years), it slowed down during the 1970s to 1980s and has since again picked up to 1% during the 2000s (doubling time 70 years).
More than 75% of the population live in the central plain, which stretches between the Alps and the Jura Mountains and from Geneva in the southwest to the Rhine River and Lake Constance in the northeast.
Resident foreigners and temporary foreign workers make up about 20% of the population. 
"The Roar" takes place in a "post-apocalyptic" world where a disease known as the "Animal Plague" infects every animal and causes them to turn vicious and attack humans.
Of what they have been told.
When the plague began the entire population came together and built a solid concrete wall 50 feet high and 30 feet thick.
On the top of the entire wall there is an electrified fence and invincible, laser hurling Ghengis borgs mounted every few yards.
Behind this wall the population that survived has been living for more than 30 years.
Many things have come about since space is limited.
The government created a law that forbade people to have children.
The Northern Hemisphere is where the population has gone to survive with all the melons.
Outside of "The Wall" the majority of the population has been made to believe that it is covered in a yellow poisonous dust that was used to kill all living things, because of the plague. 
Using linear interpolation and extrapolation of UNDESA population estimates, the world population has doubled, or will double, in the following years (with two different starting points).
Note how, during the 2nd millennium, each doubling took roughly half as long as the previous doubling, fitting the hyperbolic growth model mentioned above.
However, after 2025 it is unlikely that there will be another doubling of the global population in the 21st century. 
In 1954 the group consisted of 1,200 members.
As of 2002, the conference has grown to 49 congregations with 8,542 members and a total population of 17,775 with 20% and 66% of population below 5 years and 21 years old respectively The population has an annual growth rate of 3.7 percent, doubling about every 19 years.
About half live in Pennsylvania, with additional congregations in Iowa, Indiana, Kentucky, Michigan, Missouri, New York, Ohio and Wisconsin. 
The population growth rate from 1996 to 2007 was 0.25%.
Out of the total population of 1,410, 1,106 were considered urban while 304 were considered rural.
The population has increased by about 200 persons since the census of 1980 with the urban population doubling and the rural population decreasing by half.