Top 5 stadiums with most home runs hit?

For this season, as of the end of play on 4/24/2010 the Top 5 stadiums for home runs, by HR per at bat, in order are:

1.) Minute Maid Park (Houston, Tx)

2.) Camden Yards (Baltimore, Md)

3.) Comerica Park (Detroit, Mi)

4.) Chase Field (Phoenix, Az)

5.) Great American Ball Park (Cincinnati, Oh)