Pew Research Center Report: The Web at 25 in the U.S.

Link to report

From the summary of findings:

• Adoption.  87% of Americans use the Internet.
• Impact
• 90% of users say it's been a good thing for them personally
• 76% of users say it's been a good thing for society
• Most difficult of technologies to give up (compared with cell phones, television, email, landline telephone, social media)
• 76% describe the Internet as a "mostly kind" environment.

Source:  Wisconsin Public Library Service Data

Note:  After 1999, the annual report didn't include a yes-or-no question regarding Internet access.  There was a statistical shift to the number of computer terminals/workstations.

Safe to say, though, that public library Internet access in Wisconsin was quickly closing in on ubiquitous.

Related posts:
Pew Internet and American Life Project survey sez: 15% of Americans don't go online.  (9/28/20214) 

U.S. Census Bureau: Computer and Internet Use in the United States (Population Characteristics).  (7/25/2013)
Pew Internet and American Life Project;  Internet use at libraries.  (12/28/2012)