John dies in 1996 and, in his will, he leaves his business to his wife, Mary, and on her death to John's niece, Anne. Anne worked full time in the business from 1990.
When Mary dies in 2009, Anne inherits the business. Anne qualifies for Favourite Niece Relief because she worked in the business for five years before John's interest in the business ended (1996).
If Anne worked in the business since 1992, she would not qualify for the relief. This is because she would have been working for only four years before John's interest ended.