Belt, (La Faja de Plata), historically, is the world's most productive silver district with well over 10 billion ounces of silver production and between 63 to 75 million ounces of gold production. Many of the major mines in the belt include Pachuca, Guanajuato, Zacatecas, Fresnillo, Tayoltita, Santa Eulalia, Parral-Santa Barbara-San Francisco del Oro, and Charcas which have been in nearly continuous production since the 16th century and the first four of this list have produced over a billion ounces of silver each. The belt currently produces about 100 million ounces of silver per year from a combination of epithermal vein and carbonate replacement deposits (CRDs). Canadian companies have been at the forefront of the global expansion of mining activity, especially in Latin America and Mexico. While in the 1990's Canadian companies accounted for only 12% of mineral investment in Latin America, by the 2000's that number had risen to 33%. With this increase in investment, it has been important for the Mexican authorities to bring in new regulations that are closer to international standards. Of particular importance to mining investors have been the new environmental regulations. In the specific case of Mexico, SEMARNAP, the ministry of environment in Mexico, has aligned its policies to internationally accepted standards so exploration and mining activities would have a reduced impact on the environment. Under SEMARNAP, mineral exploration and mining require a number of environmental permits and authorizations to conform to the statutes of the Ley General del Equilibio Ecologico y Proteccion Ambiental, (LGEEPA