The line graph illustrates the alternative population of three wildlife species in North America between 2011 and 2016.
Overall, it is clear that the bear population witnessed an upward trend, while the opposite was true for the dolphin population. The bear population also had the highest figure during the period.
In 2011, the number of dolphins in the wild stood at 150.000, the highest figure that year. Then, it declined significantly in the next year and dropped to only 40.000 in 2013. From 2013 to 2015, there was a slight decrease from around 40.000 to just 1.000, respectively. Finally, the number of wild dolphins bottomed at zero species in 2016.
By contrast, starting at nearly zero species, the number of bear populations increased significantly to 100.000 in 2013. Then this figure continued to increase to 140.000 in 2015, before reaching a high of 180.000 in 2016. In addition, the number of wild whales decreased slightly from 80.000 to 50.000 between 2011 and 2012, before its fluctuation between 60.000 species during the four-year period