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:
Premier_League

Context:
Television money had also become much more important; the Football League received £6.3 million for a two-year agreement in 1986, but when that deal was renewed in 1988, the price rose to £44 million over four years. The 1988 negotiations were the first signs of a breakaway league; ten clubs threatened to leave and form a "super league", but were eventually persuaded to stay. As stadiums improved and match attendance and revenues rose, the country's top teams again considered leaving the Football League in order to capitalise on the growing influx of money being pumped into the sport.

Question:
For how many years was the 1988 television rights contract?

four