Latitude, with countries near the equator producing more females than near the poles.
Sex and the City | Sex Pistols | European Court of Human Rights | Human Rights Watch | human | Human sexuality | United States Department of Health and Human Services | Human swimming | Human | The Human League | European Convention on Human Rights | sex | Steinhardt School of Culture, Education, and Human Development | Human Genome Project | Human migration | Human leukocyte antigen | same-sex marriage | Human skull | Universal Declaration of Human Rights | human trafficking | Human Rights Campaign | Mixed-sex education | Human Torch | Human resources | human eye | Nazi human experimentation | Human settlement | Human head | Human Target | Human Development Index |
The sex ratio at birth (between male and female births) in mainland China reached 117:100 and remained steady between 2000 and 2013, substantially higher than the natural baseline, which ranges between 103:100 and 107:100.