title: Filling data down to subsequent row
body: <p>I have data that look similar to:</p>
  
  <pre><code>Alabama Age&gt;50 Value1 Value2 Value3
          Age&lt;50 Value1 Value2 Value3
  Alaska Age&gt;50 Value1 Value2 Value3
          Age&lt;50 Value1 Value2 Value3
  </code></pre>
  
  <p>I only need to keep the data for <code>Age&lt;50</code>. How can I repeat the state name to the row below it? I have created a string of the state names, but am unsure how to insert it into every other row in the first column.</p>
  
  <p>The head of my <code>data.frame</code> is:</p>
  
  <pre><code>d &lt;- structure(c("ALABAMA", "", "ALASKA", "", "ARIZONA", "", "Under 18",
          "Total all ages", "Under 18", "Total all ages", "Under 18", "Total all ages",
          "0", "1", "10", "87", "46", "303", "0", "0", "0", "36", "6", "855", "84,843",
          "", "469,145", "", "6,303,555", ""), .Dim = c(6L, 5L), .Dimnames = list(NULL,
          c("State", "", "Rape3", "Prostitution and\ncommercialized\nvice",
          "2014\nestimated \npopulation")))
  </code></pre>