Martha A. Burger has served as Senior Vice President - Human and Corporate Resources since March 2007. She served as Treasurer from 1995 to March 2007 and as Senior Vice President - Human Resources since 2000. She was the Company’s Vice President - Human Resources from 1998 until 2000, Human Resources Manager from 1996 to 1998 and Corporate Secretary from 1999 to 2000. From 1994 to 1995, she served in various accounting positions with the company, including Assistant Controller - Operations. From 1989 to 1993, Ms. Burger was employed by Hadson Corporation as Assistant Treasurer and from 1993 to 1994 served as Vice President and Controller of Hadson Corporation. Prior to joining Hadson Corporation, Ms. Burger was employed by The Phoenix Resource Companies, Inc. as Assistant Treasurer and by Arthur Andersen & Co. Ms. Burger is a Certified Public Accountant and graduated from the University of Central Oklahoma in 1982 and from Oklahoma City University in 1992.