Represent data with plots

1. The total emissions PM2.5 in United States from 1999 to 2008 using base plotting system.
2. The total emissions PM2.5 in Baltimore City, Maryland from 1999 to 2008 using base plotting system.
3. The differences between the type of source of the emissions from 1999 to 2008 for Baltimore City using ggplot2.
4. The total emissions from coal combustion-related sources across United States from 1999 to 2008 using ggplot2.
5. The total emissions from motor vehicle sources on Baltimore City from 1999 to 2008 using ggplot2.
6. Compare emissions from motor vehicle sources in Baltimore City with emissions from motor vehicle sources in Los Angeles County, California.