See this link: http://finance.yahoo.com/q/fc?s=NGX14.NYM+Futures+Chain
The natural gas futures has two issues. First, it only shows two decimal points. Natural Gas is traded with three like $4.505, not $4.50 as listed on your site.
Second, not all of the futures are listed. Nat Gas futures trade monthly. You have random months listed starting with November 2014. The spot month is April right now. The months you have listed seem randomly selected.
