General :: Script To Extract Appropriate Line From Website Using Links

I need to write a script called '~/get_birthrate' which when invoked with a two letter country abbreviation(i.e, au,ch,ni), extracts the appropriate line which contains the information about the country's birth rate from the [URL] (where "ca.html" should be replaced with the appropriate two letter abbreviation). The output should look like:

$ get_birthrate au
8.69 births/1,000 population (2007 est.)
$ get_birthrate ch
13.45 births/1,000 population (2007 est.)
$ get_birthrate ni
40.2 births/1,000 population (2007 est.)