Figure 1 - National Transportation Emissions Trends Index: 1970-1999
Figure 1 - National Transportation Emissions Trends Index: 1970-1999
(Index: 1970 = 1.0; 1990 = 1.0 for PM-2.5 and ammonia)
Excel | CSV | Graphic Version
| Year | CO | NOx | VOC | PM-10 | PM-2.5 | Lead | Ammonia |
|---|---|---|---|---|---|---|---|
| 1970 | 1.0 | 1.0 | 1.0 | 1.0 | 1.0 | ||
| 1971 | 1.0 | 1.1 | 1.0 | 1.1 | 1.1 | ||
| 1972 | 1.0 | 1.2 | 0.9 | 1.1 | 1.2 | ||
| 1973 | 1.0 | 1.2 | 0.9 | 1.1 | 1.0 | ||
| 1974 | 0.9 | 1.1 | 0.8 | 1.1 | 0.9 | ||
| 1975 | 0.9 | 1.2 | 0.8 | 1.1 | 0.7 | ||
| 1976 | 1.0 | 1.2 | 0.8 | 1.1 | 0.8 | ||
| 1977 | 1.0 | 1.2 | 0.8 | 1.1 | 0.8 | ||
| 1978 | 1.0 | 1.3 | 0.8 | 1.1 | 0.6 | ||
| 1979 | 0.9 | 1.2 | 0.7 | 1.1 | 0.5 | ||
| 1980 | 0.9 | 1.2 | 0.7 | 1.0 | 0.4 | ||
| 1981 | 0.9 | 1.2 | 0.7 | 0.9 | 0.3 | ||
| 1982 | 0.9 | 1.2 | 0.7 | 0.9 | 0.2 | ||
| 1983 | 0.9 | 1.2 | 0.7 | 0.9 | 0.2 | ||
| 1984 | 0.9 | 1.2 | 0.7 | 1.0 | 0.2 | ||
| 1985 | 0.9 | 1.2 | 0.8 | 1.0 | 0.1 | ||
| 1986 | 0.8 | 1.1 | 0.7 | 0.9 | 0.1 | ||
| 1987 | 0.8 | 1.1 | 0.7 | 1.0 | 0.0 | ||
| 1988 | 0.8 | 1.2 | 0.7 | 1.1 | 0.0 | ||
| 1989 | 0.8 | 1.2 | 0.6 | 1.1 | 0.0 | ||
| 1990 | 0.7 | 1.2 | 0.5 | 1.1 | 1.0 | 0.0 | 1.0 |
| 1991 | 0.7 | 1.2 | 0.6 | 1.1 | 1.0 | 0.0 | 1.1 |
| 1992 | 0.7 | 1.2 | 0.5 | 1.1 | 1.0 | 0.0 | 1.1 |
| 1993 | 0.7 | 1.3 | 0.5 | 1.0 | 0.9 | 0.0 | 1.2 |
| 1994 | 0.7 | 1.3 | 0.6 | 1.0 | 0.9 | 0.0 | 1.2 |
| 1995 | 0.7 | 1.3 | 0.5 | 0.9 | 0.8 | 0.0 | 1.3 |
| 1996 | 0.7 | 1.4 | 0.5 | 1.0 | 1.0 | 0.0 | 1.2 |
| 1997 | 0.7 | 1.4 | 0.5 | 1.0 | 0.9 | 0.0 | 1.4 |
| 1998 | 0.6 | 1.4 | 0.5 | 0.9 | 0.9 | 0.0 | 1.4 |
| 1999 | 0.6 | 1.4 | 0.5 | 0.9 | 0.8 | 0.0 | 1.4 |
KEY: CO = carbon monoxide; NOx = nitrogen oxides; VOC = volatile organic compounds; PM-10 = particulate matter 10 microns in diameter or smaller; PM-2.5 = particulate matter 2.5 microns in diameter or smaller.
SOURCE: U.S. Environmental Protection Agency, Office of Air Quality Planning and Standards, "National Emission Inventory (NEI), Air Pollutant Emission Trends," available at http://www.epa.gov/ttn/chief/trends/, as of January 2001.