WASHINGTON (AP) — The ranks of America's poor are greater than previously known, reaching a new level of 49.1 million — or 16 percent — due to rising medical costs and other expenses that make it harder for people to stay afloat, according to new census estimates. The numbers released Monday are part of a first-ever supplemental poverty measure aimed at providing a fuller picture of poverty. It is considered experimental and does not replace the Census Bureau's official poverty formula, which continues to determine eligibility and distribution of billions of dollars in federal aid for the poor.