title: sql list number of people born every year
body: <p>I have a table with two columns, name and year of birth(from 1960-1980). How can I write a single sql query which lists each year and the number of people born that year? something like:</p>
  
  <pre><code>      Year     Number of people born
        1960     5
        1961     3
        1962     4
        ...      ..
        1980     4
  </code></pre>