EXHIBIT 12.1

Computation of Ratio of Debt to Equity

	Year ended December 31,
Dollars in thousands	2006		2005		2004		2003		2002
Debt	$	455,136,424	$	400,914,950	$	339,394,909	$	287,454,057	$	250,767,241
Equity		169,628,002		166,353,839		170,461,385		162,116,322		161,864,679
Debt to equity		2.68		2.41		1.99		1.77		1.55