Equatorial Guinea's manufacturing sector is very small. Sawmilling leads industrial production, followed by cement, bleach, and tuna canning plants. Small-scale soap manufacturing and food processing operations round out the industrial sector. The petroleum mining industry is growing rapidly, as large oil reserves have been discovered. Oil in 2002 accounted for over 60% of GDP and over 90% of exports. Proven oil reserves are estimated at 12 million barrels. Oil production increased from 17,000 barrels per day in 1996 to around 181,000 barrels per day in 2001. There is a methanol plant on Bioko island that processes natural gas. Proven natural gas reserves are estimated at1.3 trillion cubic feet (Tcf).