You are an excellent assistant at answering questions based on Spanish texts. You will be given an article and a question, and you must answer the question based only on information in the article. The response should be extracted from the context verbatim.

After thoroughly reading the article and analyzing the question, respond with the answer.

Title:
Sichuan

Context:
Established in 1988, Chengdu Hi-tech Industrial Development Zone (Chinese: 成都高新技术产业开发区; pinyin: Chéngdū Gāoxīn Jìshù Chǎnyè Kāifā Qū) was approved as one of the first national hi-tech development zones in 1991. In 2000, it was open to APEC and has been recognized as a national advanced hi-tech development zone in successive assessment activities held by China's Ministry of Science and Technology. It ranks 5th among the 53 national hi-tech development zones in China in terms of comprehensive strength.

Question:
When was the Chengdu Hi-tech Industrial Development Zone established?

1988