Tab-delimited spreadsheets of these data are available for 1998, 1999, the past 12 months, and annual figures from1995-99.
Due to changes in our recordkeeping over time, the graphs of 1995-99 group many categories together that appear separately in the single-year graphs.
See this graph for 1998, 1999, or 1995-99.
See this graph for 1998, 1999, or 1995-99.
See this graph for 1998, 1999, or 1995-99.
The trendlines in these graphs are 2nd-degree polynomials (quadratic
equations). The 95% confidence intervals indicate two standard errors
about the mean.
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