The nation’s health care tab hit $3.5 trillion last year, or $10,739 per person, the government reported Thursday. But behind those staggering figures was some fairly good news: The rate of growth slowed for the second year in a row, according to economic experts at the federal Health and Human Services department. Health care spending increased by 3.9 percent in 2017, following a 4.8 percent increase in 2016.