AUSTIN, TX — Robocalls have become such an incessant annoyance that many Americans are increasingly wary of picking up the phone. In October alone, 5.7 billion robocalls were placed across the U.S., including 636.4 million in Texas, according to YouMail's most recent robocall index.

Nationwide, robocalls are made at a rate of 182.7 million per day, 7.6 million per hour and 2,100 per second. The average U.S. resident received 17.3 robocalls in October. The October tally is up significantly from September when about 4.5 billion robocalls were detected, according to Alex Quilici, the CEO of YouMail, a robocall blocking and tracking firm. The previous high was in March, when 5.2 billion robocalls were reported.

Why the big jump? The answer: The people behind the robocalls are getting more crafty, Quilici told Patch. "We think it's a couple of things. It's harder to get through because of blocking apps, so they have to keep making more calls to get through. And a lot of people respond to them." Residents in Austin received 42.3 million robocalls in October — 1.4 million per day, 60,000 per hour, 16 per second. The average Austin resident received 32.7 robocalls last month — nearly twice the U.S. average.

. The top 10 robocallers in Austin last month were: CALLER ID: Shelly Collins CALLER TYPE: Unknown robocaller

Shelly Collins Unknown robocaller CALLER ID: Capital One CALLER TYPE: Bank/credit card payment reminder

Capital One Bank/credit card payment reminder CALLER ID: Spectrum CALLER TYPE: Service payment reminder

Spectrum Service payment reminder CALLER ID: Synchrony Bank CALLER TYPE: Bank/credit card payment reminder

Synchrony Bank Bank/credit card payment reminder CALLER ID: AT&T Wireless CALLER TYPE: Unknown robocaller

AT&T Wireless Unknown robocaller CALLER ID: Bat Line CALLER TYPE: Unknown robocaller

Bat Line Unknown robocaller CALLER ID: Fingerhut. CALLER TYPE: Payment reminder

Fingerhut. Payment reminder CALLER ID: Spectrum CALLER TYPE: TV provider spam

Spectrum TV provider spam CALLER ID: Santander CALLER TYPE: Bank/Credit Card Payment Reminder

Santander Bank/Credit Card Payment Reminder CALLER ID: TransWorld Systems Inc. CALLER TYPE: Debt collector The 10 cities that received the most robocalls in October were:

Atlanta: 221,085,300 robocalls, up 27 percent from September Dallas: 205,081,200 robocalls, up 24 percent from September New York City: 175,637,400 robocalls, up 21 percent from September Los Angeles: 175,623,400 robocalls, up 29 percent from September Chicago: 171,866,400 robocalls, up 23 percent from September Houston: 169,378,100 robocalls, up 25 percent from September Baltimore: 122,852,700 robocalls, up 23 percent from September Newark, New Jersey: 112,404,500 robocalls, up 26 percent from September Phoenix: 108,903,500 robocalls, up 26 percent from September San Francisco Bay area: 103,622,700 robocalls, up 23 percent from September Nationally, about 47 percent of robocalls were scam calls, according to the report. The rest were legitimate — 11 percent were telemarketers, 20 percent were payment reminders, and 22 percent were alerts and other reminders.

Many robocalls direct people to press "1" on their phone keypads if they want more information, or to press "9" to be taken off the calling list. Both actions are counterproductive, signaling to the caller that a real person has been reached, Quilici said. "It's pointless to press a number," he said. "It just tells them it's an active number, so you're going to get more calls."