The national average price for a gallon of diesel gasoline dropped for the ninth consecutive week, falling by $0.07 to $3.555 as of September 9, according to the Energy Information Administration. This decline follows previous reductions over the past weeks, culminating in a total decrease of 31 cents. Compared to the same week last year, the average has decreased by 98.5 cents. Additionally, WTI crude oil is currently priced at $70.27 on the New York Mercantile Exchange.