SALT LAKE CITY (AP) — Utah is the nation’s fastest-growing state, and new data shows it remained the youngest over the last decade. The Census Bureau released new data Thursday that provides the most detailed portrait yet of how the state has changed since 2010. The number of people under 18 grew by nearly 9% in Utah even as the number of children in the U.S. shrunk because of declining birth rates and aging baby boomers. Though the state has the country’s highest portion of young people at 29%, that portion is still lower than a decade ago, when it was about 32%.