Q: This task is about writing a correct answer for the reading comprehension task. Based on the information provided in a given passage, you should identify the shortest continuous text span from the passage that serves as an answer to the given question. Avoid answers that are incorrect or provides incomplete justification for the question.
Passage: Switzerland has one of the best environmental records among nations in the developed world; it was one of the countries to sign the Kyoto Protocol in 1998 and ratified it in 2003. With Mexico and the Republic of Korea it forms the Environmental Integrity Group (EIG). The country is heavily active in recycling and anti-littering regulations and is one of the top recyclers in the world, with 66% to 96% of recyclable materials being recycled, depending on the area of the country. The 2014 Global Green Economy Index ranked Switzerland among the top 10 green economies in the world. Question: When did Switzerland ratify the Kyoto Protocol
A:
2003