The economy received a boost in the early 1990s with the arrival of several hundred thousand immigrants from the former Soviet Union. As a significant number of the immigrants were highly educated, Israel accelerated its privatization to encourage the high-skilled workers to stay. The new labor also attracted foreign direct investment. Israel's growth over the past decade has been commensurate with Western developed nations as is its per capita GDP (PPP), which is about $35,000/year – the third highest (behind Bahrain and the UAE) of the Middle Eastern countries not dependent on natural resources. It also has the highest economic complexity index of all the countries in the Middle East. Israel is described as "very highly developed" on the UN's Human Development Index, ranking 16th among 187 world nations and highest in the Middle East in 2012.