BeginPackage["Wikicode`SodiumSulfate`"]
Production::usage="Production[date] gives the annual world sodium sulfate production from the specified date."
Begin["`Private`"]
Production[from_Integer]:=Select[sodium sulfateData["Production"],DateDifference[{from},#[[1]]] >= 0&]
sodiumSulfateData["Production"] =
MapAt[{Round@#} &, #, 1] & /@
Import["http://minerals.usgs.gov/ds/2005/140/ds140-nasul.xlsx"][[1,
58 ;; 97, {1, 9}]]
End[]
EndPackage[]
