Since the beginning of the decade the production of natural gas in the UK has had an increasing growth rate due to the liberalization process of the industry. The reason being is that electricity generation is cheaper using natural gas compared to other fuels. On the other hand, electricity generating plants can be built in stages, allowing for greater flexibility according to market changes. In Norway, primary energy production is much higher than its internal demand. Its rate of Energy Self Sufficiency in 1995 was 860%. The UK's primary energy consumption is closer to its production level. In 1995 its rate of Energy Self Sufficiency was 110%.