Swift Wheels Logistics, a national transport company operating across multiple states in the US, is pursuing ISO 50001 certification. The company\'s operations are subject to varying state regulations concerning fuel efficiency standards, emission control mandates, and renewable energy portfolio standards. Senior management is keen on establishing robust energy performance indicators (EnPIs) to track progress, benchmark performance across different operational regions, and ensure compliance with diverse regulatory requirements. Considering the complex operational environment and the need for meaningful comparisons, which of the following EnPIs would be most effective for Swift Wheels Logistics in meeting the requirements of ISO 50001 and demonstrating tangible improvements in energy performance while accounting for the regulatory differences? The company’s primary business is transporting goods, measured in ton-miles, across different states.