It takes 9 zeros to express a billion of anything in our numerical system. According to the Census Bureau, as of tomorrow (July 11th) the world population will reach 7.58 billion. The Bureau predicts however, the population growth rate will begin declining (1%) starting 2020-2021. Between 1920 and 1980, the population more than doubled from 2 billion to almost 4.5 billion. The Bureau’s projections and an article on how it keeps track of world population can be viewed HERE.