The two given pie charts present information about the percentage of different types of pollutants between 1997 and 2007.
Overall, the data are divided into seven various types: domestic sewage, offshore oil, marine, litter, farm waste, industrial waste,and pollutants from air. The proportion of domestic sewage and offshore oil increased during this period, the others experienced a decline throughout the period.
The percentage of domestic sewage rose steadily from 18 percent to 29 percent between 1997 and 2007. Furthermore, the proportion of offshore oil almost tripled from 5 percent to 14 percent throughout the period.
Meanwhile, the proportion of pollutants from air, which was the biggest share in 1997, experienced a slight drop from 30 percent to 29 percent between 1997 and 2007. Even though it showed a fall, it remained the biggest proportion with domestic sewage with a percentafe of 29 percent. The percentage of litter declined dramatically from 4 percent to 0 percent. Moreover, the proportion of farm waste halved from 4 percent to 2 percent between 1997 and 2007. Similarly, the percentage of industrial waste almost halved from 17 percent to 9 percent during this period. The proportion of marine decreased modestly by 5 percent at the end of the period.