The line graph illustrates the percentage of good-quality river water in four distinct countries between 1995 and 2010, with projections extending to 2018. Overall, countries A and B consistently maintained high water quality standards, whereas countries C and D showed greater volatility.
Countries A and B began the period with high percentages of 96% and 94% respectively. Both countries saw a gradual upward trend, with Country A peaking at 98% in 2010 before dipping slightly to 96% by 2018. Country B followed a similar trajectory, reaching a peak of 98% in 2013, before ending the period at 97%.
In contrast, Country C experienced a decline from 94% in 1995 to a low of 87% in 2008, followed by a steady recovery to 96% by 2018. Country D exhibited the most erratic performance; after an initial rise from 84% to 92% between 1995 and 2000, the quality fluctuated significantly, dropping to 84% in 2008, rising to 86.5% in 2010, and finally declining back to 84% by 2018. By the end of the period, Country D remained the lowest performer among the four nations.