Dutch disease first became apparent after the Dutch discovered a huge natural gas field in Groningen in 1959. The Netherlands sought to tap this resource in an attempt to export the gas for profit. However, when the gas began to flow out of the country, its ability to compete against other countries' exports declined. With the Netherlands' focus primarily on the new gas exports, the Dutch currency began to appreciate, which harmed the country's ability to export other products. With the growing gas market and the shrinking export economy, the Netherlands began to experience a recession. This process has been witnessed in multiple countries around the world including but not limited to Venezuela (oil), Angola (diamonds, oil), the Democratic Republic of the Congo (diamonds), and various other nations. All of these countries are considered "resource-cursed".