UK <a href="https://en.wikipedia.org/wiki/Income_Tax" class="extiw" title="w:Income Tax">w:Income Tax</a> and <a href="https://en.wikipedia.org/wiki/National_Insurance" class="extiw" title="w:National Insurance">w:National Insurance</a> (<a href="https://en.wikipedia.org/wiki/2004" class="extiw" title="w:2004">w:2004</a>-<a href="https://en.wikipedia.org/wiki/2005" class="extiw" title="w:2005">w:2005</a>)  (made the chart myself with <a href="https://en.wikipedia.org/wiki/Gnuplot" class="extiw" title="w:Gnuplot">w:Gnuplot</a> and <a href="https://en.wikipedia.org/wiki/Perl" class="extiw" title="w:Perl">w:Perl</a>)
<a href="https://en.wikipedia.org/wiki/User:Edward" class="extiw" title="w:User:Edward">Edward</a> (<a href="https://en.wikipedia.org/wiki/User_talk:Edward" class="extiw" title="w:User talk:Edward">talk</a>) (<a href="https://en.wikipedia.org/wiki/Special:ListFiles/Edward" class="extiw" title="w:Special:ListFiles/Edward">Uploads</a>)
<span class="int-own-work" lang="en">Own work</span>