Another study made by the University College London in collaboration with Mexico's National Institute of Anthropology and History found that the frequencies of blond hair and light eyes in Mexicans are of 18% and 28% respectively, surveys that use as reference skin color such as those made by Mexico's National Council to Prevent Discrimination and Mexico's National Institute of Statistics and Geography reported a percentages of 47% in 2010 and 49% in 2017 respectively. A study performed in hospitals of Mexico City reported that an average 51.8% of Mexican newborns presented the congenital skin birthmark known as the Mongolian spot. The Mongolian spot appears with a very high frequency (85-95%) in Asian, Native American, and African children. The skin lesion reportedly almost always appears on South American and Mexican children who are racially Mestizos, while having a very low frequency (5–10%) in Caucasian children. According to the Mexican Social Security Institute (shortened as IMSS) nationwide, around half of Mexican babies have the Mongolian spot.