TV RATINGS

New series continued to slide down the Nielsen list during the ninth week of the 1987-88 television season. More than half of the bottom-30 rated shows debuted this season while only one--NBC’s piggyback hit “A Different World” starring Lisa Bonet in a time slot immediately following “Cosby”--reached the Top 20. By contrast, miniseries seemed to find renewed life: Nov. 16 and 17 broadcasts of NBC’s “Poor Little Rich Girl” finished 10th and 17th, respectively, and Part One of CBS’ “The Gambler III” came in 12th with its Sunday showing. Weekly network averages: NBC, 17.3 rating/28 share; CBS, 13.8/22; ABC, 12.6/21. Evening news ratings: CBS 12.1, ABC 11.4, NBC 11.1. (One Nielsen point equals 886,000 homes; “share” refers to the percentage of households watching a particular program.) The complete Nielsens appear on Page 20.

* NBC’s wavering “Miami Vice” pulled up its ratings to finish 24th last week with an installment featuring the lovable Sonny Crockett getting hitched to pop star Sheena Easton. The show scored its highest rating of the season and narrowly defeated competing “Dallas” for the first time this TV year.

SHOW POINTS SHARE WEEK 1. The Cosby Show 31.0 47 11/22 (NBC) 33.9 51 11/15 2. A Different World 28.2 43 11/22 (NBC) -- -- 11/15 3. Cheers 26.4 41 11/22 (NBC) 26.4 40 11/15 4. Night Court 26.1 40 11/22 (NBC) 24.7 38 11/15 5. 60 Minutes 23.2 37 11/22 (CBS) 23.7 36 11/15 * Miami Vice 16.8 27 11/22 (NBC) 14.1 23 11/15