The supplied bar graph depicts the rate of renewable energy in total energy supplied of 4 nations between 1997 and 2010.
In general, there was an upward trend in the percentage of renewable energy in Iceland and Sweden, while the reverse trend was true for that of Australia and Turkey. Notably, Iceland was the leading country throughout the period.
In terms of the ratio of renewable energy in Iceland and Turkey, in 1997 the figure for Iceland was around 45% and increased steadily to 60% and 70% in 2000 and 2010, respectively. Similarly, those for Turkey witness the slight growth to 40% in 2000, whilst in the next decade it declines to 32% and was only a half of the figure for Iceland.
Regarding remaining countries, in 1997, nearly 10% energy supply of Australia came from sustainable resources, then halved to 5% in 2010. Conversely, the figure for Sweden experienced the marginal rise from 5% in 1997 to approximately 10% at the end of the period.