Specifications include, but are not limited to: National Grid is unable to predict the amount of load that will be required to meet the needs of any customer group. National Grid’s customers are free to leave Default Service at any time to take service from competitive suppliers. The ability of customers to enroll or return to Default Service is described in Appendix A. To assist Respondents in determining the potential load requirements, National Grid is able to provide the following information on its Power Procurement Website: For MA Default Service: Aggregate historical wholesale hourly load information for MA Default Service (since March 1, 1998); Aggregate historical wholesale hourly loads for MA Default Service by customer group (since November 1, 2000); Historic hourly loads by SMD Load Zone and customer group for MA Default Service (since March 1, 2003);