user: Question: What was the last appearance of actor/actress is Pam Ferris?
Columns: ['Actor/Actress', 'Character', 'First Appearance', 'Last Appearance', 'Duration', 'Total']
Types: ['text', 'text', 'text', 'text', 'text', 'real']
Sample row: ['Mathew Horne', "Gavin 'Gav' Shipman", '13 May 2007', '1 January 2010', '2007–2010', 20.0]
SQL:

assistant: SELECT "Last Appearance" FROM "Table" WHERE "Actor/Actress" = 'Pam Ferris';