For example, although in Peru corruption was pervasive elsewhere, government reforms that lowered tax rates managed to increase tax revenue from 8.4% of GDP in 1991 to 12.3% in 1998, and increase the number of taxpayers from 895,000 in 1993 to 1,766,000 in 1999. Of course, not all programs are successful, but some effective cases of procurement and revenue reform have benefits 100 times higher than the costs.