In this task, you're given a passage, further information available on a particular linked term from the statement, and a question. Your job is to generate the answer to the question by using the information provided. If there is no clear answer obtainable, output 'none'.

Passage: In 1975 his orchestral Fourth Sonata (written 197475) won the Scottish National Orchestra's Ian Whyte Award. Subsequent orchestral works include the widely performed Night Music (1976), Sonata No. 5: Landscape (197781), and a First Cello Concerto, commissioned by the BBC for the 1984 Proms: these last two have been recorded by Unicorn-Kanchana. In 1989 Cortege was given its first performance by the Orchestra of the Royal Opera House under Bernard Haitink, and Quatrain by the London Symphony Orchestra and Michael Tilson Thomas. This was the first of a series of LSO commissions, followed by Machines and Dreams for their 1991 Childhood Festival, Memorial in 1993 with Mstislav Rostropovich as conductor, and a Second Cello Concerto for Rostropovich in 1996. In 1990 he made a setting of three comic poems by Wendy Cope, Strugnell's Haiku. Matthews was Associate Composer with the LSO from 1992 until 1999. The orchestral version of Hidden Variables was a joint commission for the LSO and the New World Symphony Orchestra, who gave the American premiere in Miami under Michael Tilson Thomas in 1992; in the same year the Cleveland Orchestra gave the American premiere of Machines and Dreams. Collins Classics released a CD of Matthews' LSO commissions in 1996 to celebrate his 50th birthday.
Link Information: Mstislav Leopoldovich "Slava" Rostropovich (, ; 27March 192727 April 2007) Question: How old was Mstislav Rostropovich the year Matthews won the Ian Whyte Award?
Answer: 48