title: reorder currency x-axis in ggplot
body: <p>I am quite new in ggplot and I have a question to relabelling the x-axis.</p>
  
  <pre><code>ggplot(female_income)+geom_bar(mapping=aes(x=household_income))
  
  </code></pre>
  
  <p>but the result is</p>
  
  <p><img src="https://i.stack.imgur.com/bU2bB.png" alt="Income Distribution for Females with the wrong x-axis order"></p>
  
  <p>I want a result like this</p>
  
  <p><img src="https://i.stack.imgur.com/OtvJa.jpg" alt="Income Distribution for Females with the right x-axis order"></p>