title: gnuplot histogram does not visualize small numbers
body: <p>I'm just taking the first look at gnuplot today and using the histogram example, I wanted to build a small example as from the tutorial, only I changed the input numbers from 50,000 something to 100-range and it is not visualized correctly.
  Here's the dat file</p>
  
  <pre><code>Region   Denmark   Netherlands     Norway  Sweden    
  1891-1900       500  400  300   200 
  </code></pre>
  
  <p>And this is the gnuplot script</p>
  
  <pre><code>set terminal pngcairo
  set output 'histograms.2.png'
  set boxwidth 0.9 absolute
  set style fill   solid 1.00 border lt -1
  set key inside right top vertical Right noreverse noenhanced autotitles nobox
  set style histogram clustered gap 5 title  offset character 0, 0, 0
  set datafile missing '-'
  set style data histograms
  set xtics border in scale 0,0 nomirror rotate by -45  offset character 0, 0, 0
  set xtics  norangelimit font ",8"
  set xtics   ()
  set title "US immigration from Northern Europe\n(same plot with larger gap between clusters)" 
  set yrange [ 0.00000 : 3000. ] noreverse nowriteback
  i = 22
  plot 'immigration.dat' using 1:xtic(1) ti col, '' u 2 ti col, '' u 3 ti col, '' u 4 ti col
  </code></pre>
  
  <p>As seen in here: </p>
  
  <p><img src="https://i.stack.imgur.com/JJNO4.png" alt="enter image description here"></p>
  
  <p>the first column is wrongly visualized. any ideas?!</p>