The number of infant deaths in the United States declined 2 percent in 2006, government researchers reported Wednesday, but the rate still remains well above that of most other industrialized countries. Infant mortality has long been considered one of the most important indicators of the health of a nation and the quality of its medical system. In 1960, the United States ranked 12th in the world. By 2004, the latest year for which comparisons were issued by the Centers for Disease Control and Prevention, the U.S. ranking had dropped to 29th. This international gap has widened even though the United States devotes a far greater share of its national wealth to health care than other countries. In 2006, Americans spent $6,714 per capita oil health care