Most statistics are out of date to some degree by the time they are published. Just because a report is published in 2000 does not mean the data is from the most recent few years. Current health data is often based on extrapolations of older data, such as U.S. Census data, compiled every ten years, or smaller sample sizes. Again, check to see when and how the data was collected. In most cases you will probably see at least a 3-5 year time lag between data collection and a published report.
Most health data is compiled and distributed by the federal government.
It is notoriously difficult to track down government resources since federal reports etc. are not well indexed in other resources. When possible, see if the reporting agency has the statistics you need. If not, then you will need to search the journal literature in a bibliographic database like Medline or CancerLit . It may be difficult to always determine what type of statistical data is available from a citation or abstract. When in doubt, read the article to make sure that you are not missing potential data.