How many wood fence posts (4" x 4" in particular) were sold in the
U.S. in 2004, 2003, or 2002?  The type of wood is irrelevant (pine,
treated, etc.) just as long as it is wood and not vinyl, metal, or
other materials.  The stats from just Home Depot and/or Lowes would be
fine too.  Pressure-treated lumber is most commonly used for fence
posts.  Thank you so much!