Tourism is the mainstay of the small, open Aruban economy, with offshore banking and oil refining and storage also important. The rapid growth of the tourism sector over the last decade has resulted in a substantial expansion of other activities. Construction has boomed, with hotel capacity five times the 1985 level. In addition, the reopening of the country's oil refinery in 1993, a major source of employment and foreign exchange earnings, has further spurred growth. Aruba's small labor force and low unemployment rate have led to a large number of unfilled job vacancies, despite sharp rises in wage rates in recent years. Tourist arrivals have declined in the aftermath of the 11 September 2001 terrorist attacks on the US. The government now must deal with a budget deficit and a negative trade balance.