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.
Q: Paragraph: McPartlin and Donnelly first met while working on the BBC children 's drama Byker Grove in 1989 . After a shaky start , they soon became best friends . They have achieved such popularity as a duo that they are hardly ever seen apart on screen . It is reported that they are each insured against the other 's death , with the amount reportedly being around £ 1,000,000 . Their inseparability has led to their receiving joint nominations for many awards . They are both managed by the James Grant Group .
Question: when did ant and dec join byker grove

A: 
1989