Although significant progress in reducing child deaths globally has been made since the 1990s, an estimated 5.9 million children under the age of 5 still died from mostly preventable causes in 2015, while 2.4 billion people lacked access to adequate sanitation, a report from the United Nations finds. The Sustainable Development Goals Report 2016 (HTML or PDF, 56 pages) presents data on selected indicators from the UN's seventeen Sustainable Development Goals and highlights critical gaps and challenges for the global community, including the need to reduce inequality by gender and income. According to the report, in 2012 one in eight people worldwide lived in extreme poverty, while 1.1 billion people did not have electricity. The report also found that in 2014 about 50 percent of the planet's urban population was exposed to air pollution levels at least 2.5 times above the safety standard set by the World Health Organization and that, as of 2015, more than twenty-three thousand species of plants, fungi, and animals faced a high probability of extinction. The report notes that to ensure that the SDGs are translated into effective action, the global community will require better disaggregated data for those most at risk.