The most important institution in the city is the market. There are four traditional markets with the most important of these located just off the main square. The main market building was built by the city in 1970, with booths in this market now worth as much as $30,000 pesos. The owners of the booths pay a small trust fee which is used for public works projects. These are supplemented by tianguis markets in the Guichivere neighborhood on Wednesdays and one in Reoloteca neighborhood on Sundays. The market is the center of nearly all commerce in the city, with 95% of the goods small enough to carry sold there. As a result, the city lacks department, electronics, clothing, jewelry and other types of stores.