title: Regex for two years separated by a forward slash
body: <p>I am new to learning Regex and I am struggling with this basic issue. I want to make sure a string is in a format like: 2000/2001 or 2010/2011.</p>
  
  <p>I tried something like: ^[2000-2900]./.[2000-2900]$ but I know this is wrong!</p>