Aged 16-74. IUSNET - Participating in social networks (creating user profile, posting messages or other contributions to Facebook, Twitter, Instagram, Snapshat, etc.)
  1 - Ticked
  0 - Not ticked
  9 - Not applicable (IU=Blank or IU ne 1)

Individuals Participating in social networks
sum of IND_WGHT where (IUSNET=1)