4. The U. S. Municipal Solid Wastes data below show the generation of waste in pounds per person per day and total waste generation in million tons per year.
Year
1980
1970
1980
1990
2000
2002
2006
2007
2008
Daily Waste
Total Waste
(pounds per person/day) (millions of tons pear year)
27
88.1
3.3
121.1
37
151.1
4.5
2052
46
238.3
4.6
239.4
46
251.3
46
254.6
45
249.6
Percentage
Recycled
6.4
66
96
162
245
295
323
33 1
332
a) According to the data in the graph, in which year did recycling have the greatest effect on total
waste by percentage of waste recycled? Explain. (2 points)