Constantly losing internet connection, only briefly, then connection restored - this has been going on for a few months

Intermitent, but persistent interruptions to my service.  We've run all the diagnostics in the app and even had service to the house.  The last guy changed the service line from the box in the backyard to the house.  However, the problem persists.  From my command prompt, I ran a couple of tests    ping -n 100 www.google.com.  This test of 100 packets had a loss of 19%.  I also ran a test to the modem itself    ping 10.0.0.1 -t   and the result was a 0% loss.  This has been a very frustrating issue, and I'm looking for what I need to do to solve the issue I'm having.