title: ggplot2 stacked line plot acting funny
body: <p>My stacked plot is going all wonky in the later years.  Could someone look at my code and tell me where I went wrong?  I thought my code was identical to the example code (both below).</p>
  
  <p>I am not very experienced with ggplot2 plot stacking so I might be making a simple error.</p>
  
  <p>I wanted something that looked like:
  <img src="https://i.stack.imgur.com/XPwYD.jpg" alt="Stacked Plot"></p>
  
  <p>The code to produce that produces the above stacked plot is available as part of The R Graphics Cookbook and can be found at <a href="http://blog.revolutionanalytics.com/2013/02/a-review-of-the-r-graphics-cookbook.html" rel="nofollow noreferrer">Revolutions R Blog Post</a>.<br>
  <strong>From The R Graphics Cookbook</strong>
       library(ggplot2)
       library(gcookbook)</p>
  
  <pre><code> ggplot(uspopage, aes(x=Year, y=Thousands, fill=AgeGroup)) +
   geom_area(colour="black", size=.2, alpha=.4) +
   scale_fill_brewer(palette="Blues", breaks=rev(levels(uspopage$AgeGroup)))
  </code></pre>
  
  <p><strong>I thought I had pretty much duplicated the syntax.</strong>  But, it seems to me that I must have made a mistake somewhere.</p>
  
  <pre><code> lawsize &lt;- as.data.frame(read.csv("https://raw.githubusercontent.com/EconometricsBySimulation/wild-monkey/master/usc.csv"))
  
   ggplot(lawsize, aes(x=Year, y=KB, fill=factor(Name)))+
   geom_area(colour="black", size=.2, alpha=.4)
   scale_fill_brewer(palette="Blues", breaks=rev(levels(lawsize$Name)))
  </code></pre>
  
  <p><img src="https://i.stack.imgur.com/iDcB0.png" alt="My Stacked Plot"></p>
  
  <p>Thanks for your consideration in this matter! F</p>