USA sales figures are unusual in that only the brands that are listed make up the total. If a minor brand's sales are not there, then it is as if they don't exist. In countries where the data is compiled from registration figures, then all are included in the total, even if some are within the other figure. In the US, it seems that sales figures are released by the maker voluntarily. It only affects smaller marques such as Aston Martin who seem to chose not to reveal sales.
Land Rover had modest growth in comparison with its worldwide 2012 sales, due mainly to the 'small' Evoque not being the size Americans prefer. The new Range Rover will do the business for the brand in 2013. The Fiat 500 is catching on stateside, after a cautious start.