Statistically, children under the age of five worldwide are most vulnerable to disease and premature death. But according to a new UNICEF report, the number of under-five child deaths has dropped dramatically by 41 percent since 1990. Improved healthcare, cheaper and more widely available vaccinations and health education are all factors in this advance. But 6.9 million children died in 2011 before their fifth birthday, causing UNICEF Deputy Director Geeta Rao Gupta to celebrate the progress yet call the situation “unfinished business.”