The District offers broader access to public preschool than any state in the nation, according to a survey released Tuesday, which showed that the city continues to expand its early childhood education programs even as enrollment in pre-kindergarten declined nationally for the first time in a decade.

The annual “State of Preschool” report from the National Institute for Early Education Research, based at Rutgers University, showed that 94 percent of four-year-olds and 80 percent of three-year-olds were enrolled in the District’s public preschool programs in 2012-2013.

By contrast, across the country 28 percent of four-year-olds and only 4 percent of three-year-olds are enrolled in public preschool.

Mayor Vincent C. Gray (D) led the push to rapidly expand pre-kindergarten programs when he was chairman of the D.C. Council, and has said many times that he sees early education as essential to boosting achievement, especially among the city’s most disadvantaged children.

“The District has worked hard and invested millions of dollars to achieve universal pre-K, and we are only beginning to see the incredible dividends we will reap from this crucial investment in our most precious resource,” Gray said in a statement.

In recent years the city’s preschool programs have drawn more families, including middle-class families, into the city’s public schools, helping to reverse a decades-long enrollment decline.

The city spends more on preschool — $14,690 per child — than any state, followed by New Jersey at $12,070, according to the NIEER survey. On average, states spend $4,026 per child, but South Carolina and Nebraska each reported spending less than $2,000 per child.

Unlike some states, the District’s preschool programs are full-day, and preschool teachers are required to hold a bachelor’s degree. Education Secretary Arne Duncan has praised the District’s public preschools — which are operated by traditional public schools, public charter schools and community-based organizations — as a model for the kind of preschool programs the Obama administration would like to see offered around the country.