A 2005 newspaper article states that "The highway fatality rate sank to a record low last year, the government estimated. But the overall number of traffic deaths increased slightly. Overall, 42800 people died on the nation's highways in 2004, up from 42643 in 2003, according to projections from NHTSA".
Answer the following questions:
a. Is the figure $42800$ an inferential statistic or a descriptive statistic?
b. Is the figure $42643$ an inferential statistic or a descriptive statistic?
I have the answer that a. ($42800$) is inferential, because it references a change from the previous year, while b. ($42643$) is descriptive, as it's a data point stated in the past.
Question: I don't understand how a. is different from b. For an inferential statistic we need a sample and a population we make our inferences about and I can't see how we distinguish here between a sample and a population as we just have numbers of deaths in 2004 and 2003, respectively.
So, why is a. inferential?