_dta:
  1.  by Jean Roth , jroth@nber.org , 19 Apr 2019
  2.  NBER URL: www.nber.org/data/npi.html
  3.  Source Page: http://download.cms.gov/nppes/NPI_Files.html
  4.  Source File URL: download.cms.gov/nppes/NPPES_Data_Dissemination_Apr_2019.zip
  5.  Source Text File: npidata_pfile_20050523-20190407.csv*

  obs:     5,800,357                          
 vars:             2                          20 Apr 2019 22:43
 size:    81,204,998                          (_dta has notes)
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              storage   display    value
variable name   type    format     label      variable label
------------------------------------------------------------------------------------------
npi             str10   %10s                  National Provider Identifier (NPI)
penumdate       float   %td                   Provider Enumeration Date
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Sorted by: npi