title: Pandas box plot error on one datapoint
body: <p>I'm working on a box-plot using pandas.</p>
  
  <p>My DataFrame looks like this</p>
  
  <pre><code>Year                 2013      2014      2015      2016      2017
  dfMin            1.091603  0.973346  1.040000  0.855209  1.079500
  dfLowerQuartile  1.727191  1.684009  1.275601  1.136703  2.262654
  dfUpperQuartile  2.225000  2.000000  1.857570  2.120644  2.435724
  dfMax            2.687323  2.350000  2.105000  2.250000  2.566467
  </code></pre>
  
  <p>My chart code looks like this</p>
  
  <pre><code>chartDF.boxplot(grid=False, figsize=(9,4))
  </code></pre>
  
  <p>Leading to a plot looking like this
  <a href="https://i.stack.imgur.com/4tKZk.png" rel="nofollow noreferrer"><img src="https://i.stack.imgur.com/4tKZk.png" alt="enter image description here"></a></p>
  
  <p>I am puzzled at the lower value in 2017 coming out as a point.</p>
  
  <p>Does anyone know how to fix this issue?</p>