Extended image description for Figure 2
The vertical axis of the graph represents millions of tonnes and it ranges from negative 30 to 35, in increments of 5. The horizontal axis represents the years from 1961 to 2013, in increments of 1. The approximated data from the graph are as follows: 1961: 4 percent, 1962: 5 percent, 1963: 1 percent, 1964: negative 5.5 percent, 1965: negative 5 percent, 1966: negative 5 percent, 1967: 3.5 percent, 1968: 3 percent, 1969: 6 percent, 1970: 3 percent, 1971: 5.5 percent, 1972: negative 4 percent, 1973: negative 11 percent, 1974: 3 percent. 1975: negative 7 percent, 1976: negative 6 percent, 1977: negative 4.5 percent, 1978: negative 8 percent, 1979: negative 7 percent, 1980; negative 13.5 percent, 1981: negative 15 percent, 1982: negative 19.5 percent, 1983: negative 20 percent, 1984: negative 25 percent, 1985: negative 20 percent, 1985: negative 14.5 percent, 1986: negative 17, 1987: negative 20, 1988: negative 12.5, 1989: negative 13, 1990: negative 14, 1991: negative 18, 1992: negative 27, 1993: negative 11, 1995: negative 4, 1996: negative 3, 1997: negative 3.5, 1998: negative 0.5 percent, 2000: 4 percent, 2001: 2 percent, 2002: negative 1 percent, 2003: 5 percent, 2004: 21 percent, 2005: 8 percent, 2006: 6 percent, 2007: 17 percent, 2008: 15 percent, 2009: 33 percent, 2010: 17 percent, 2011: 20 percent, 2012: 30 percent, 2013: 25 percent.