More installed capacity was required by a growing demand, which, combined with the geothermal resource constraints, significantly changed the energy portfolio, so that in 1998, the installed capacity of geothermal power accounted for 57%, and by 2004, 73% of system was based on natural gas. As a result, the energy dependence of Baja California increased, and the net generation in 1996 showed a 2-to-1 geothermal to fuel oil ratio, which by 2004, was nearly a 1-to-1 geothermal to natural gas ratio. However, the use of natural gas increased the overall efficiency of conversion, which rose from 20% in 1996 to 26% in 2004.