post-2010 state split

[jGaboardi]

From the Specs for Crosswalk Deliverables document.

Split files by state: All of the above (including "existing" files)

• Idea: Single state file for 2010-2019 target zones except for AZ, CA, NY, which need separate files for 2010 & later target zones.
  • For NY: 2010 in one file; 2011-2019 in another
  • For CA & AZ: 2010-2011 in one file; 2012-2019 in another

[jGaboardi]

Also see here from https://nhgis.org/user-resources/geographic-crosswalks.