Submitted on: 11 January 2004.
Revised on: 02 February 2004.
Accepted on: 28 February 2004.
Scandinavian Actuarial Journal
Submitted on: 05 November 2006.
Revised on: 26 November 2006.
Accepted on: 20 December 2006.
Scandinavian Actuarial Journal
Submitted on: 23 December 2014.
Revised on: 18 January 2015.
Accepted on: 27 January 2015.
Scandinavian Actuarial Journal
Submitted on: 29 March 2015.
Revised on: 19 April 2015.
Accepted on: 15 May 2015.
Scandinavian Actuarial Journal
http://reply.papertrans.cn/3/276/27505/27505-15.png
http://reply.papertrans.cn/3/276/27505/27505-16.png
Submitted on: 30 July 2004.
Revised on: 07 August 2004.
Accepted on: 24 August 2004.
Scandinavian Actuarial Journal
Submitted on: 31 May 2014.
Revised on: 10 July 2014.
Accepted on: 05 August 2014.
Scandinavian Actuarial Journal
http://reply.papertrans.cn/3/276/27505/27505-19.png
Submitted on: 18 July 2005.
Revised on: 28 August 2005.
Accepted on: 13 September 2005.
Scandinavian Actuarial Journal