title: Print ggplot y axis values in 10 thousands
body: <p>I am having some trouble changing my y-axis values. </p>
  
  <p>This is my df:</p>
  
  <pre><code>Years &lt;-c("1997","1997","1997", "1998","1998","1998", "1999", "1999","1999","2000", "2000", "2000")
  Type &lt;-c("Export","Import", "Production","Export","Import", "Production", "Export","Import", "Production","Export","Import", "Production")
  Amount &lt;- c(12063595,19465000,38591914,14929732,20941620,42570725,33598846,30533486,62633597,39755626,30129958,49493053)
  df &lt;-data.frame(Years, Type, Amount)
  </code></pre>
  
  <p>And this is the graph I have produced:</p>
  
  <pre><code>ggplot(data=df, aes(x=Years, y=Amount, group=Type, colour=Type)) +
    geom_line(size=1.1) +
    scale_colour_manual(values=cbPalette)+
    theme_bw()+
    ylab("Timber   [in 10,000 m3(r)]") +
    xlab("Years")  +
    expand_limits(y=0) + guides(colour = guide_legend(override.aes = list(size=3)))+
    theme(legend.title=element_blank(), 
          legend.position="top",
          legend.text = element_text(size=20),
          axis.text.x  = element_text(size=20), axis.title.x=element_text(size=20),
          axis.text.y  = element_text(size=20), axis.title.y=element_text(size=20))
  </code></pre>
  
  <p>As you can see I have very high numbers (highest = 62,633,597) and right now they are displayed scientifically (6e+07). 
  I would like to display the values "in 10 thousands" as indicated in the label and I have absolutely no idea if there is a way to do that.</p>