Delaney Smith, a first grader at Mid-Prairie Elementary School in Kalona, Iowa, practices writing her numbers in Arabic under the Dept. of Education's National Security Language Initiative program. (U.S. State Dept.)

(CNSNews.com) -- Arabic is the fastest growing language in the U.S., with the number of Arabic speakers growing by 29 percent between 2010 and 2014, according to a recent study by the Pew Research Center.

Over the longer period from 2000 to 2014, the number of Arabic speakers in the U.S. nearly doubled, rising from 615,000 in 2000 to 1.1 million by 2014, according to the study, which analyzed data from the U.S. Census Bureau.

As a result, census questionnaires will be available in Arabic for the first time in 2020, Pew reports.

“The number of people ages 5 and older who speak Arabic at home has grown by 29% between 2010 and 2014 to 1.1 million, making it the seventh most commonly spoken non-English language in the U.S.,” the study said.

The study noted that the number of people who speak Spanish at home has only grown 6 percent during that same time period.

“Among those who speak Arabic at home, 38% were not proficient in English – that is, they report speaking English less than ‘very well',” the study added, noting that this percentage is similar to the 42 percent of people who speak Spanish at home who are not proficient in English.

The Pew study pointed to the U.S.’ growing Muslim population, which it documented in another study last January, as an explanation for the trend.

The January study cited an increase in Muslim immigration over the last 20 years and the fact that “American Muslims tend to have more children than Americans of other religious faiths.”

According to that study, the Muslim population in the U.S. in 2015 was an estimated 3.3 million, or about 1 percent of the total U.S. population. In 2010, the Muslim population was about 2.6 million.