The California Healthy Kids Survey in 1999 and 2001 asked 7th, 9th, and 11th graders in San Luis Obispo County whether they smoked tobacco. In 1999, 6% of 7th graders, 17% of 9th graders, and 23% of 11th graders admitted smoking tobacco while in 2001 the corresponding figures were 3%, 13%, and 22%. Create a comparative bar chart showing bars for 7th graders together, bars for 9th graders together, and bars for 11th graders together. Comment on any interesting features of the chart.