TV ratings for Thursday, May 15th are in.  Here’s a brief rundown:

• The season finale of CBS’ The Big Bang Theory scored the comedy’s most-watched finale ever, hitting a 4.8 rating in the 18-49 demo and scoring 16.29 million viewers.  That’s up 26% from last week’s rating and even with last year’s season finale.  Elsewhere on the network, The Millers rose 26% to a 2.4 rating and 9.88 million viewers, Bad Teacher was up 8% to a 1.4 rating and 5.53 million viewers, and Elementary’s finale was down 7% to a series low 1.4 rating and 7.34 million viewers.
• The season finale of ABC’s Grey’s Anatomy was even with last week’s 2.5 rating and garnered 8.61 million viewers.
• NBC’s second installment of Rosemary’s Baby dipped 9% from Sunday’s episode with a 1.0 rating and 3.31 million viewers.
• Over on The CW, The Vampire Diaries was up 14% to a 0.8 rating and 1.57 million viewers, though it was down 27% from last year’s season finale. Reign matched last week’s 0.5 rating and scored 1.26 million viewers.