BeginPackage["Wikicode`Helium`"]
Production::usage="Production[date] gives the annual world helium production from the specified date."
Begin["`Private`"]
Production[from_Integer]:=Select[heliumData["Production"],DateDifference[{from},#[[1]]] >= 0&]
heliumData["Production"] =
MapAt[{Round@#} &, #, 1] & /@
Import["http://minerals.usgs.gov/ds/2005/140/ds140-heliu.xlsx"][[1,
6 ;; 82, {1, 10}]]
End[]
EndPackage[]
