From press reports:
An encore telecast of Saturday Night Live, hosted by Sigourney Weaver and featuring musical guests The Ting Tings, averaged a 4.0 household rating/10 share in metered-market households. In the 25 markets with local people meters, Saturday Night Live averaged a 2.2 rating/9 share in adults 18-49.
That's pretty good for a repeat. The average original SNL this season has averaged about a 4.5 household rating in the metered market numbers. The original telecast of the show in January had among the best ratings of the season.