Good news for those that love numbers–Sega Sammy Holdings has released their 2017 annual sales report, including sales from both Atlus and Sega. The report is 147 pages long, but reveals some promising numbers for a number of the company’s IPs. Thanks a lot to Gematsu for reading through the fluff to find the raw numbers!
Here are Sega Sammy’s sales numbers for a variety of their IPs, provided by Gematsu:

Megami Tensei series (Launched 1987) ? Approx. 7.2 million units across 28 total editions (packaged and digital total)
Persona series (Launched 1996) ? Approx. 8.5 million units across 13 total editions (packaged and digital total)
Sonic the Hedgehog series (Launched 1991) ? Approx. 360 million units / downloads (packaged and digital total) Puyo Puyo series (Launched 1991, Sales Account for after 1998) ? Approx. 25 million units / downloads
Yakuza series (Launched 2005) ? Approx. 10.5 million units / downloads across 75 total editions (packaged and digital total)
Beast King series (Launched 2001) ? Approx. 490,000 units across 15 total editions (pachislot and pachinko machine and amusement machine total)
Phantasy Star series (Launched 1987) ? Approx. 4.5 million Phantasy Star Online 2 IDs (cumulative total for registered IDs)
Chain Chronicle series (Launched 2013) ? Approx. 10 million downloads across two total editions (packaged and digital total)
Sega feat. Hatsune Miku Project series (Launched 2009) ? Approx. 5.5 million units / downloads...