Missouri has not seen a decade of population growth like this one for 100 years. The census bureau says Missouri grew by almost 480,000 people this decade, 9% increase. State demographer Ryan Burson says it’s the biggest population boom in a century in two categories, percentage growth and overall growth. He says you have to go back to the 1880’s to see that level of growth in Missouri. The first census in Missouri was taken in 1810. We had fewer than 20,000 people here then. The census bureau says our population now is almost 5.6 million people.