Because Nissan/Infiniti sales hit an all-time high in 2013, reported here:
"Nissan continued its strong performance, posting its best annual U.S. sales total in the company’s history. Including Nissan and Infiniti, the automaker sold 1.25 million vehicles in 2013, including 109,758 in December."
And through November 2014 sales for Nissan only have hit 1.26 million, the most ever, reported here:
"With one month remaining in 2014, Nissan has now set a record for most U.S. sales in a year in the company's history with 1,269,577, up 11.5 percent for the year."