D.1. Economic Statistics: Since all meaningful statistics in economic analysis are statistics about Economic Goods, they only show relative valuations. (From 1.3.4)
E.1. A price alone, or its trend, a quantity of something, etc all are useful statistics for purposes other than economic analysis. Within economic analysis, due to the definition of the subject, meaningful is only something which shows a relation of scarce-substitutable means and multiple ends. Accordingly, statistic too must show such a relation. Hence, a price, or a trend of price, without its comparison with prices of other available goods is by definition of Economic Good not a statistic about Economic Good. We have the price of apples, quantities sold of apples, but only when in our analysis we plug-in other prices and quantities which consumers can substitute with apples, we can formulate something meaningful about prices of apples which are now relative prices (prices in relation with all others).
Reference: Chapter 03 of Robbins, L. (2007). An essay on the nature and significance of economic science.