An analysis by the Pew Research Center of Census data has determined that Arabic is now the fastest-growing language being spoken in U.S. homes.

Pew looked at American Community Survey data from 2006 to 2014 that asked what languages are spoken in an individual’s home. Between 2010 and 2014, the number of respondents who spoke Arabic climbed 29%, from about 865,000 to about 1.1 million. Here’s the chart:

The Census question does not imply that Arabic is the only language spoken at home, or even the primary language, just that it is one language spoken at home by 1.1 million Americans. From 2000 to 2010, Hindi was previously the fastest-growing language other than English spoken at home.

Pew attributes the growth to a wave of immigrants coming from Middle Eastern and North African countries in the past few years. Indeed, data from the Arab American Institute shared with Fusion shows the the percentage of U.S. immigrants from this region has surged since the beginning of the Iraq war, and experienced a significant spike in 2010.

Among Arabic-speaking countries, the U.S. saw the greatest influx of immigrants from Iraq between 2009 and 2013 (the most recent year for which the AAI had data available), at about 89,000; followed by Egypt at 36,000 and Somalia at about 23,000.

Urdu was the second-fastest-growing non-English language being spoken at home, at 23%. Urdu is an official language of Pakistan, and is also spoken in parts of India.

Pew also notes that although they don’t all speak Arabic, Muslims tend to have high fertility rates. Among women ages 40 to 59, Pew says, Muslim women report having had an average of 2.8 children each, compared with 2.1 children among all U.S. women.

Maya Berry, executive director of the Institute, said it is likely the Census is undercounting the number of Arab-Americans in the U.S. That’s because the Census has stopped asking about an individual’s ancestry to focus on their ethnicity, which they have defined much more narrowly.

“As with any form, if you don’t have real estate on the form hard to capture [the status of] a community,” she said by phone.

The Institute estimates that there are closer to 3.7 million Arab-Americans now living in the U.S.

In fact, this issue was the basis for Pew’s analysis. The Census is now considering adding an item that would allow individuals to identify as Middle Eastern and North African on the 2020 Census, something PBS notes would give them “greater political clout and access to public funding.”