Title: “The Gender Imbalance Crisis: Examining the Factors Behind the Disparity of Men and Women in the World’s Population”

this long question below is the question that needs be  answered in the essay 
According to the United Nations, there are 73 million more men in the world than women and these numbers are concentrated in the lower  age groups. What factors create these statistics?
also please add in-text citations 
just don’t use Wikipedia as a source