Q: Given a passage and a question, find the answer to the question based on the passage. The answer should consist of only one word that lies in the span of only one of the sentences in the passage.
Paragraph: The first speed camera was installed in 1991 . A camera that was installed on the M40 motorway and recorded 400 instances of speeding within 40 minutes . The Association of British Drivers was formed the same year and campaigned vigorously against speed cameras .
Question: when was the first speed camera introduced in the uk

A:
1991