user: Question: What years was El Mabrouk the area of operation?
Columns: ['Client', 'Years of Operation', 'Area of Operation', 'Country', 'Services']
Types: ['text', 'text', 'text', 'text', 'text']
Sample row: ['Agoco', '1991-current', 'Sarir field', 'Libya', 'Drilling, workover']
SQL:

assistant: SELECT "Years of Operation" FROM "Table" WHERE "Area of Operation" = 'El Mabrouk';