Siri remains the most popular virtual assistant with 41.4 million monthly active users in the U.S., according to a new report from measurement firm Verto Analytics out this morning, but it has seen a 15 percent decline since last year – or 7.3 million monthly users. In addition, the study found that engagement with Siri has also dropped by nearly half during this period, from 21 percent to 11 percent ICT Solution.

Meanwhile, Amazon Alexa usage has been skyrocketing – jumping 325 percent in monthly active users – that is, from 0.8 million to 2.6 million monthly users, as its user engagement also increased from 10 percent to 22 percent during the same time frame nuskin.

Cortana has seen an increase as well, growing from 0.2 million monthly users in the U.S. to 0.7 million, or a 350 percent increase. Its user engagement tripled, from 19 percent to 60 percent nuskin.