Observe the table below and answer the following question:

Year	Population	Consumption of electricity (GW)
2015	20	25
2016	30	40
2017	40	60
2018	50	80
2019	60	100

1 GW = 100 Million Watt

Population in Million

In which year did electricity consumption grow by 50%?

Correct option is A

Formula Used:
​$$\text{Percentage Increase} = \left( \frac{\text{Current Year Value} - \text{Previous Year Value}}{\text{Previous Year Value}} \right) \times 100$$​​
Solution:
From 2015 to 2016: $$\left( \frac{40 - 25}{25} \right) \times 100 = 60\%$$​​
From 2016 to 2017: $$\left( \frac{60 - 40}{40} \right) \times 100 = 50\%$$​
From 2017 to 2018: $$\left( \frac{80 - 60}{60} \right) \times 100 = 33.33\%$$​
From 2018 to 2019: $$\left( \frac{100 - 80}{80} \right) \times 100 = 25\%$$​​
Electricity consumption grew by 50% in the year 2017 (from 2016 to 2017).