Worldwide oil and gas drilling contractor GlobalSantaFe Corporation reported that the company's worldwide SCORE, or Summary of Current Offshore Rig Economics, for December 2005 was up 6.7 percent from the previous month's SCORE. GlobalSantaFe's SCORE compares the profitability of current mobile offshore drilling rig dayrates to the profitability of dayrates at the 1980- 1981 peak of the offshore drilling cycle. In the 1980-1981 period, when SCORE averaged 100 percent, new contract dayrates equaled the sum of daily cash operating costs plus approximately $700 per day per million dollars invested. In addition to a worldwide SCORE covering key types of competitive offshore drilling rigs in key drilling markets, a separate SCORE is calculated for certain types of rigs and certain regions to indicate the relative condition of rig markets.