Shark Tank had a significant week-to-week drop in the demo last night, down 17%. However, the two-hour special edition of 20/20 — “One Moment in Time: The Life of Whitney Houston” — saw big gains.

You can check out our ratings pages for Shark Tank, 20/20, and Primetime (MIA last night) to see the week-to-week ratings trends, averages, rankings, and more.

Here’s a press release from ABC with their spin on last night’s numbers:

A Big “20/20” Drives ABC to its Most-Watched Friday in Over 2 Years

ABC won Friday among Adults 18-49, posting a season high and leading its network rivals on the evening for the 4th time in 5 weeks.

· In fact, ABC marked its most-watched Friday in more than 2 years and hit its highest Adult 18-49 number on the night since December 2010 – since 1/1/10 and 12/31/10, respectively

From 8-9pm, ABC’s Shark Tank earned second place in Adults 18-49, beating out Fox’s Kitchen Nightmares by 15%. In addition, the ABC unscripted series once again stood as the #1 broadcast show of the night with Teens 12-17.

· Posting big year-over-year gains for ABC in the hour, Shark Tank was up by 2.0 million viewers and by 50% in Adults 18-49 over an original Supernanny on the same night last year.

From 9-11pm, ABC’s 20/20 dominated its 2-hour time period in Adults 18-49 and Adults 25-54, leading runner-up CBS by 33% and 22%, respectively. During its final hour from 10-11pm, ABC’s 20/20 outdrew NBC’s Dateline by 4.2 million viewers and more than doubled its newsmagazine competition in Adults 25-54 (+113%) and Adults 18-49 (+109%). ABC’s 20/20, “One Moment in Time: The Life of Whitney Houston,” took an in-depth look at the voice of the century, from her record-setting achievements and musical legacy, to her rocky personal life and battle with addiction, as well as the latest developments about the superstar’s final days.

· Jumping sharply week to week in Total Viewers (+55%), Adults 25-54 (+47%) and Adults 18-49 (+43%), ABC’s 20/20 drew its biggest audience in over 2 years and scored 17-week highs in both key Adult measures – since 2/5/10 and 10/21/11, respectively.

What do you think? Were you watching any ABC programming last night?