Data extracted into Excel

Hey guys.
I was really hoping to extract some data into an excel spreadsheet, but it seems like when I’m extracting financial numbers i get a deviation from alle the postings to the total costs. f.ex. my air traffic control fees are 13.319 AS$ but when I add all of the 12 postings I get 13.318. Does anybody know how decimals are handled and if this is fixable? I tried inspecting the websites code but I still dont see any decimals.