What has contributed to the increase in the population of the Earth in recent centuries?

The population growth on our planet is taking place at a very significant pace. This is associated with an increase in human life expectancy, as well as with the natural processes of birth and death rates. It should be noted that the increase does not come at the expense of all fear. So in the countries of China, India, the increase is rapid, in Russia, Ukraine, Western Europe, significant growth is not observed. One of the reasons is the development of the level of medicine, which allows to extend the average age of a person.