title: Add +1 (>1) after every time a condition is met
body: <p>(sorry, really don't know how to better phrase this question)</p>
  <p>I have a column &quot;have&quot; with 1s and 0s. I want to create a new column &quot;want&quot; where, each time a 1 has occurred, the value of 0 increases to 2, then 3, then 4, etc. 0 should never be 1.</p>
  <p>Example:</p>
  <pre><code>data &lt;- data.frame(have = (c('0', '0', '0', '0', '1', '0', '1', '0', '0', '1')), 
                     want = (c('0', '0', '0', '0', '1', '2', '1', '3', '3', '1')))                       
  </code></pre>