Question: What was the former name of the sponsor of the 1987 Daily Mirror Greyhound Derby?

Context paragraphs:
1983 English Greyhound Derby: The 1983 Daily Mirror Greyhound Derby took place during June with the final being held on 25 June 1983 at White City Stadium.  The winner I'm Slippy received £25,000 and the competition was sponsored by the Daily Mirror.

1987 English Greyhound Derby: The 1987 Daily Mirror Greyhound Derby took place during June with the final being held on 30 June 1987 at Wimbledon Stadium.  The winner Signal Spark received £30,000 and the competition was sponsored by the Daily Mirror.

1995 English Greyhound Derby: The 1995 Daily Mirror/Sporting Life Greyhound Derby Final took place on 24 June 1995 at Wimbledon Stadium.  The winner Moaning Lad received £50,000.  The competition was sponsored by the Sporting Life and Daily Mirror.

1997 English Greyhound Derby: The 1997 Daily Mirror/Sporting Life Greyhound Derby took place during May & June with the final being held on 28 June 1997 at Wimbledon Stadium.  The winner Some Picture received £50,000.  The competition was sponsored by the Sporting Life and Daily Mirror.

1989 English Greyhound Derby: The 1989 Daily Mirror Greyhound Derby took place during June with the final being held on 24 June 1989 at Wimbledon Stadium.  The winner Lartigue Note received £40,000.  The competition was sponsored by the Daily Mirror.

1984 English Greyhound Derby: The 1984 Daily Mirror Greyhound Derby took place during June with the final being held on 23 June 1984 at White City Stadium.  It was the last time that White City held the event due to impending closure.  The winner Whisper Wishes received £25,000 and the competition was sponsored by the Daily Mirror.

Daily Mirror: The Daily Mirror is a British national daily tabloid newspaper founded in 1903.  It is owned by parent company Trinity Mirror.  From 1985 to 1987, and from 1997 to 2002, the title on its masthead was simply "The Mirror".  It had an average daily print circulation of 716,923 in December 2016.  Its Sunday sister paper is the "Sunday Mirror".  Unlike other major British tabloids such as "The Sun" and the "Daily Mail", the "Mirror" has no separate Scottish edition - this function is performed by the "Daily Record" and "Sunday Mail" which incorporate certain stories from the "Mirror" that are of Scottish significance.

1985 English Greyhound Derby: The 1985 Daily Mirror Greyhound Derby took place during June with the final being held on 22 June 1985 at Wimbledon Stadium.  It was the first time that Wimbledon hosted the event following the closure of the White City Stadium.  The winner Pagan Swallow received £25,000 and the competition was sponsored by the Daily Mirror.

1986 English Greyhound Derby: The 1986 Daily Mirror Greyhound Derby took place during June with the final being held on 30 June 1986 at Wimbledon Stadium.  The winner Tico received £25,000 and the competition was sponsored by the Daily Mirror.

1988 English Greyhound Derby: The 1988 Daily Mirror Greyhound Derby took place during June with the final being held on 30 June 1988 at Wimbledon Stadium.  The winner Hit The Lid received £30,000 and the competition was sponsored by the Daily Mirror.

Supporting paragraphs: 1987 English Greyhound Derby Daily Mirror
Answer: The Mirror