Year,Quantity (000't) 2015,39919.00 2014,39432.00 2013,41054.00 2012,36342.00 2011,36836.00 2010,34004.00 2009,29298.00 2008,27110.00 2007,28481.00 2006,29808.00 2005,26643.00 2004,26803.00 2003,25797.00 2002,26138.00 2001,25939.00 2000,23055.00 1999,21043.00 1998,23236.00 1997,26700.00 1996,17535.00 1995,18312.00 1994,19967.00 1993,15660.00 1992,13432.00 1991,13135.00 1990,10585.00 1989,10101.00 1988,12679.00 1987,9709.00 1986,11204.00 1985,10377.00 1984,9528.00 1983,10948.00 1982,10089.00 1981,10360.00 1980,11900.00 1979,11173.00 1978,11383.00 1977,9171.00 1976,9458.00 1975,8520.00 1974,7634.00 1973,7986.00 1972,7911.00 1971,8349.00 1970,7818.00 1969,7642.00 1968,6976.00 1967,6597.00 1966,6955.00 1965,7421.00 1964,7306.00 1963,7390.00 1962,6731.00 1961,6038.00 1960,5889.00