Apple Pay’s transaction volume increased by 450% in the past quarter when compared to Q2 2016. CEO Tim Cook revealed the payment system’s growth during a conference call on Tuesday. Much of its growth is coming from Apple Pay’s expansion into new markets.

The service can be used in 15 markets, including the US, China, Canada, Japan, France, and the UK.

No mention of Apple Pay’s user count was provided, nor did Cook reveal how much those transactions are worth.

Apple Pay has been available since 2014, allowing iOS users to make contactless payments