OBS_VALUE: Additional Source: Open Market Operations in the Bank of Mexico, http://www.banxico.org.mx/politica-monetaria-e-inflacion/material-de-referencia/intermedio/politica-monetaria/instrumentacion-de-la-politica-monetaria/%7BBD2DAABD-E7D4-9CF4-F2D6-C24FF4F1BCBD%7D.pdf