The table shown below gives the approximate number of pieces of mail handled by the united states postal service for different years.
how many more pieces of mail were handled by the united states postal service in 1995 than in 1965?
year. approximate number of pieces of mail handled
1950 4.5 * 10^10
1965 7.2 * 10^10
1980 1.0 * 10^11
1995 1.8 * 10^11
2010 1.7 * 10^11