The long-term growth perspective of the Indian economy remains positive due to its young population and corresponding low dependency ratio, healthy savings, and investment rates, increasing globalisation in India and integration into the global economy. The economy slowed in 2017, due to shocks of "demonetisation" in 2016 and the introduction of the Goods and Services Tax in 2017. Nearly 60% of India's GDP is driven by domestic private consumption and continues to remain the world's sixth-largest consumer market. Apart from private consumption, India's GDP is also fueled by government spending, investment, and exports. In 2019, India was the world's ninth-largest importer and the twelfth-largest exporter. India has been a member of the World Trade Organization since 1 January 1995. It ranks 63rd on the Ease of doing business index and 68th on the Global Competitiveness Report. With 500 million workers, the Indian labour force is the world's second-largest as of 2019. India has one of the world's highest number of billionaires and extreme income inequality. Since India has a vast informal economy, barely 2% of Indians pay income taxes. During the 2008 global financial crisis the economy faced a mild slowdown, India undertook stimulus measures (both fiscal and monetary) to boost growth and generate demand; in subsequent years economic growth revived. According to the 2017 PricewaterhouseCoopers (PwC) report, India's GDP at purchasing power parity could overtake that of the United States by 2050. According to World Bank, to achieve sustainable economic development India must focus on public sector reform, infrastructure, agricultural and rural development, removal of land and labour regulations, financial inclusion, spur private investment and exports, education, and public health.