privileges after the Conquest. Urban area Eight of the city's eighteen traditional barrios or neighborhoods are located in San Andrés. The division of the city into barrios, and into two halves, began in the pre Hispanic period. However, after the Spanish conquest of the Aztec Empire, the barrios were reorganized around parish churches, each given a patron saint. The San Andrés barrios are San Miguel Xochimehuacan, Santiago Xicotenco, San Pedro Colomoxco, Santa María Coaco, La Santísima, San Juan Aquiahuac, San Andresito and Santo Niño. Most of these barrios have a patron saint's name prefix before an indigenous name, which remains from the pre-Hispanic period. The neighborhoods closest to the center are urbanized, with those on the edges of the city maintaining more of their rural character, with economies based on agriculture and brick making. The unity of the city is maintained via a complicated system of social events and sponsorship to pay for them, which is rotated around the various barrios. Most of what distinguishes San Andrés from San Pedro is its historically indigenous character. The division began in the latter pre Hispanic period after the Toltecs and Chichimecas conquered the city in the 13th century. They pushed the subdued Olmec-Xicallans to the east of the city. They also built a new temple to Quetzacoatl, where the San Gabriel monastery is now, leaving the Cholula pyramid as the religious focus of the southern part of the city. During the colonial period, San Andrés would remain mostly indigenous and relatively isolated economically while San Pedro's population became mestizo quickly. Today, San Andrés is still more residential and has a higher percentage of indigenous than San Pedro. As of 2005, there were 1,845 people who spoke an indigenous language in San Andrés, with the population growing from 45, 872 to 80,118 people from 1990 to 2005. Over ninety percent of the population identifies as Catholic with less than four percent identifying as Evangelical or Protestant. Although the Cholula Pyramid and the San Gabriel monastery are only blocks from each other, the Pyramid is part of San Andrés, marking the beginning of this municipality. Because of the Cholula pyramid archeological site and because a number of streets on the San Andrés side are too narrow to permit vehicular traffic, the municipality has a mounted police force, with red jackets and hats similar to those of the Royal Canadian Mounted Police. It was created