June 30, 2011

December 31, 2010

Revolving Credit Facility, principal due at maturity in December 2012; interest payable periodically at variable interest rates. The weighted average rate at June 30, 2011 and December 31, 2010 was 0.9% and 1.5% respectively.

$

125,000

$

177,966

6.25% Senior Notes, principal due at maturity in March 2013;interest payable semi-annually in March and September at 6.25%.

375,000

375,000

6.75% Senior Notes, principal due at maturity in January 2014; interest payable semi-annually in January and July at 6.75%.

150,000

150,000

7.75% Senior Notes, principal due at maturity in June 2017;interest payable semi-annually in June and December at 7.75%. These notes were issued with a $13.4 million discount, of which $10.7 million and $11.4 million was unamortized at June 30, 2011 and December 31, 2010, respectively.

454,294

453,602

$

1,104,294

$

1,156,568