The RIAA’s just-released 2017 year-end report on the U.S. music business is an eye-opener. The big news is that streaming accounted for a whopping 65% of revenue, spurring a second consecutive year of growth for the first time in this century. The last time that happened was 1999, just before Napster turned the biz upside down.

What’s more, subscription revenue blew past the $4 billion milestone for the first time behind a 63% year-over-year revenue jump. Overall, subs grew to a 47% share of the market, with what appears to be still-increasing momentum. Ad-supported revenues grew as well—by 35%.

Interestingly, physical media, while it dipped to $1.5b, is holding up better than digital downloads, which plummeted to $1.3b. Percentage-wise, physical took a 17% slice of the pie, while downloads slimmed to 15%. CDs and vinyl last outpaced downloads in 2011. And vinyl actually experienced a 10% uptick.

So there’s something to celebrate at both poles of the market—but let’s call it cautious optimism.

RIAA chief Cary Sherman put things in perspective, noting, “We’re delighted by the progress so far, but to put the numbers in context, these two years of growth only return the business to 60% of its peak sizeâ€Š—â€Šabout where it stood 10 years agoâ€Š—â€Šand that’s ignoring inflation. And make no mistake, there’s still much work to be done in order to make this growth sustainable for the long term.”

Read Sherman’s full statement here

Read RIAA chief analyst Josh Friedlander’s breakdown here