An estimated 51.3 million Americans or 17.6% of the population were uninsured for at least part of the year in 2005, down from 51.6 million and 17.9% in 2004, the Centers for Disease Control and Prevention reports. The data are from the 2005 National Health Interview Survey, which measures lack of health insurance coverage at the time the respondent was interviewed, as well as for the prior 12 months and longer. Roughly 41.2 million people (14.2% of the population) were uninsured at the time they were interviewed in 2005, about 900,000 fewer than the previous year, although there was no significant change in the percentage of uninsured Americans under 65.