White babies are now outnumbered by minority babies, according to new population estimates from the Census Bureau.

In 2015, racial and ethnic minorities made up 50.2 percent of babies under a year old. That year, there were 1,995,102 minority babies born, just slightly more than the 1,982,936 white babies born.

The 2015 data was released Thursday, as was updated data for previous years. These new figures show that in 2013, minority babies also outnumbered non-Hispanic white babies by about 1,000 births. In 2014, white babies were outnumbered by about 16,000.

Original data from 2011 showed that white babies were in the minority, but those figures were revised in 2013 to show that the white infants were still the majority. But the new information released Thursday shows that the original figures were in fact correct, and minority births outpaced white ones.

While whites are expected to become the minority in the U.S. population in the coming decades — estimates run from 2044 to 2055 — it has been difficult to predict exactly when the shift will come. Fertility rates are impacted by a number of factors, including the health of the economy, and immigration flows can also be unpredictable.

Census bureau data, like the birthrate figures released Thursday, indicate that the shift from a majority white nation to one with no majority racial or ethnic group is starting with the youngest age groups in the country. In 2015, 50.3 percent of children younger than 5 were minorities.

Tracking such figures can also be a challenge, because different data sources use different metrics to determine a child’s race. The National Center for Health Statistics doesn’t represent mixed-race mothers as such in its data, while Census Bureau data is reported to reflect children of multiple races.