title: Statistics of positive impact of TDD/BDD
body: <p>Everyone knows about some relevant statistics about positive impact of using test/behavior driven development in real projects. I know statistics can be very misleading, but it would be nice to see something like: </p>
  
  <blockquote>
    <p>"when started using TDD, we rose productivity and reduced bugs introduction by XY %...".</p>
  </blockquote>
  
  <p>It would be really nice to show this numbers to managers/customers, when explaining need of writing tests (there are still some people thinking we don't have time for this...)</p>
  
  <p>Thanks</p>