Even as National Public Radio turns to digital in an effort to embrace a younger audience, its member stations have seen growth in on-demand listening over the past year. Numbers for its live digital streams, however, are flat in favor of podcast listening.

Data shared at last month’s Public Radio Super Regional conference by Steve Mulder, NPR’s senior director of audience insights, reveals that among 163 tracked stations, downloaded hours of on-demand content increased 18% from January to August 2015. The audience for NPR podcasts, meanwhile, grew 21% from fall 2014 to fall 2015, while the total hours of NPR podcasts downloaded rose a robust 45% over the same period. This was aided by the success of NPR’s show “Invisibilia” early in the year. As of spring 2015, 5%-10% of hours spent listening to public radio was via podcasts.

Radiotopia, the podcast network helmed by Public Radio Exchange (PRX), reported in the conference session that NPR’s 13 shows have reached a total of 9 million monthly downloads, up from 6 million monthly downloads for 11 shows in May. “That’s just tremendous growth,” Mulder said in a story in Current. “That’s faster growth than any other channel, for sure, in terms of where listening is happening.”

PRX COO Kerri Hoffman encouraged public radio execs to embrace side podcasting projects, even if they are not immediate revenue drivers. As Current reports, discouraging them, she said, could lead to a loss of new content ideas or staffers leaving, while podcasts have the potential to attract a younger audience.

NPR’s live streams, meanwhile, were flat from August 2013 to August 2015.