MEXICO CITY -- The money sent home by Mexicans living in the U.S. registered its biggest drop since record-keeping began 12 years ago.

The Bank of Mexico said remittances in August dropped 12 percent to US $1.9 billion. That compares to US $2.2 billion in August 2007.

The central bank said Wednesday that remittances had reached US $15.5 billion in the first eight months of this year, 4 percent less than the same period the year before.

Remittances began dropping this year as the U.S. economy slowed and the U.S. government stepped up enforcement of its borders with record deportations and increased border security.

Remittances are Mexico's second-largest source of foreign income, next to oil exports.