The U.S. public has been worn down by the stunning growth of the nation’s robocalling problem over the past year, culminating in a new monthly record of 4.2 billion robocalls received nationwide in August, the highest number of robocalls ever recorded in a single month since the YouMail Robocall Index launched in 2015. The volume equals some 136.2 million calls placed every day during August, or 1,576 robocalls for every second of the month.

In the first eight months of this year, robocalls were up 33.2% to 28.5 billion total calls, compared to 21.4 billion in the first eight months of 2017. That steady increase has been due mainly to more Americans who have avoided answering their phones, causing the dialers to place still more calls in their efforts to get through.

These latest monthly figures come from YouMail, a free robocall blocking solution for mobile phones. YouMail uses its patented smart blocking technology to block unwanted robocallers by making sure the user’s phone doesn’t ring, and then plays an out-of-service message that leads them to think they dialed an invalid number. YouMail identifies problematic numbers and robocalls using a combination of its recently patented audio fingerprinting technology, call patterns, and consumer feedback.

YouMail provides the YouMail Robocall Index to estimate of robocall volume across the country and in particular area codes each month. This estimate is formed by extrapolating from the behavior of the billions of calls YouMail has handled for its users, and these statistics are regularly cited by the Federal Communications Commission (FCC) as a definitive source for national data trends.

“As the cost of placing these calls approaches zero for many ruthless robocallers, there is little reason to expect this problem to decline anytime soon,” said YouMail CEO Alex Quilici. “You wouldn’t run your PC without antivirus software, so why would you run your mobile phone without a robocall blocking app?”

How Robocalls Break Down

Scam calls continued to grow In August, up to an estimated 1.76 billion robocalls, or nearly 42% of all robocalls made in the month, up from 1.44 billion robocalls in July. In contrast, there was a decline in Alerts and Reminder robocalls in August, the types of robocalls people usually want. These types of robocalls were down over 33% after fairly steady call volumes in recent months. The result is that a larger percentage of the overall robocalls are ones that people generally don’t want.

The top five scam types have changed dramatically over the course of the year. In August, the top five scams were Health Insurance Scams, Interest Rate Scams, Easy Money Scams, Search Listing Scams, and Home-Related Scams.

There has been an explosion of health and health insurance related scams (409 million) that use a variety of pretenses to collect personal information or payments for insurance that’s never delivered or owed. There has also been a big increase in “Easy Money” scams, which are calls promising very simple ways to quickly make a lot of money, all of which tend to require an initial or ongoing monetary investment. However, as the school year begins, there has been a relative decline in student loan scams (no longer in the top five scams).