In which year did primary sources record the lowest growth in total energy…

Concept

For consecutive periods, growth can be measured as the absolute increase or as the percentage increase: percentage growth = ((current total − previous total) / previous total) × 100. Comparing every interval on the same basis identifies the least growth.

Application

1. For 2007–08: increase = 15,547 − 14,868 = 679; percentage growth = (679 / 14,868) × 100 ≈ 4.57%.

2. For 2008–09: increase = 16,277 − 15,547 = 730; percentage growth = (730 / 15,547) × 100 ≈ 4.70%.

3. For 2009–10: increase = 16,889 − 16,277 = 612; percentage growth = (612 / 16,277) × 100 ≈ 3.76%.

4. For 2010–11: increase = 17,857 − 16,889 = 968; percentage growth = (968 / 16,889) × 100 ≈ 5.73%.

Cross-check

The absolute increases are 679, 730, 612, and 968 peta joules. The least absolute increase and the least percentage increase both occur in 2009–10.

Result

Therefore, primary sources recorded the lowest growth in total energy production in 2009–10.