fuel used annually in the United States by 2030, and of at least 50 percent by 2050, as compared to the average carbon intensity of all aviation fuel used in the United States in 2005. (4) Requirements In promulgating regulations under paragraph (2), the Administrator shall— (A) establish a benchmark for the average carbon intensity of aviation fuels for each calendar year, beginning with the first full calendar year that begins 2 years after the date of enactment of this subsection, suitable to achieving the targets specified in paragraph (3)