The number of robocalls last month hit pre-pandemic levels for the first time in a year, averaging over 159 million calls per day—roughly 1,911 calls per second—according to robocall-prevention service YouMail.

All totaled, Americans received 4.6 billion robocalls last month, a 15% increase over January. At the current pace, the group says, there will be more 51 billion robocalls by the end of 2021, a significant leap from the 45.9 billion received last year.

The pandemic has many unimaginable consequences, but one of the most surprising was the drop-off in robocalls early last year. In April, there were less than 3 billion made—the lowest figure in two years. As people got used to working from home, though, the spam and scam calls began to increase – and have soared so far this year.

February saw the biggest increase in scam calls, accounted for roughly 48% of the total volume. The bulk of those were warranty scams, which are a fast-growing area for criminals who use robodialers. Health-related scams were also on the rise, as people search for news and availability of the COVID-19 vaccine.

Atlanta, Ga. and Dallas, Texas saw the most robocalls overall last month, but citizens of Baton Rouge, La. and Memphis, Tenn. received the most robocalls per person.

Congress has passed a law attempting to put an end to robocalls, but it hasn’t been very effective so far, due to loopholes. The Federal Communications Commission and the Federal Trade Commission identified them as the top complaint in 2020.