Indian voters are deciding on their next prime minister and one key issue that could sway voters is how much Prime Minister Narendra Modi has done with the country's economy.

India's economy is the fastest growing large economy in the world. The United Nations expects India's current population of 1.3 billion to keep growing and surpass China by 2024.

However, the country is facing a few obstacles.

A few years ago, Prime Minister Modi, promised to add 10 million jobs to help boost the economy.

That hasn't really happened. The unemployment rate now sits at a 45-year high. And GDP per capita, which is a measure of wealth across a country, lags behind rivals like China by a wide margin.

Can India keep growing at such a fast pace? And if it does, at what cost?