The rich got richer when Nielsen re-released premiere-week viewership estimates that included same-week DVR playback.

While some modestly rated programs may have shot up by bigger percentages — especially those in crowded timeslots — it was the top-rated program on each of the major nets that gained the most viewers.

ABC’s “Grey’s Anatomy,” CBS’ “CSI,” NBC’s “Heroes” and Fox’s “House” each added about 1 rating point to their previously reported adults 18-49 national rating in Nielsen’s “live plus seven” ratings, which includes not only live viewing and same-day DVR playback but also all DVR usage within a week of its original broadcast. Each show also gained about 2 million total viewers.

For example, “Grey’s Anatomy” went from an 8.9 “live plus same day” average in the demo to a 9.9, while its total-viewer count rose from 20.96 million to 22.97 million.

The broadcast nets had been curious to see how much of the ratings declines for some favorites, as well as sluggish starts for some rookies, could be attributed to the time-shifting of shows by auds. With DVR homes now accounting for roughly 20% of Nielsen’s national sample — more than double the roughly 9% of premiere week in 2006 — more and more viewers are watching programs on their own timetables.

And nowhere is this happening more than in Thursday’s crowded 9 o’clock hour, where top-10 demo performers “Grey’s Anatomy,” “CSI” and “The Office” go head to head to head.

In the next-day Nielsens reported two weeks ago, “Grey’s Anatomy” showed a 20% year-to-year decline in adults 18-49 rating (8.8 vs. 11.0), but its dropoff is trimmed to 14% (9.9 vs. 11.5) when comparing its “live plus seven” numbers for both seasons.

Things also improved for “CSI,” whose “live plus same day” rating of 8.2 was a reported year-to-year gain of 6%; in “live plus seven,” the lift was 12%. And benefiting most was NBC’s “The Office,” whose initially reported 19% year-to-year gain (5.1 vs. 4.3) balloons to 29% (5.8 vs. 4.5).

Among first-year Big Four shows that benefited from auds having a full week to play them back on their DVRs, NBC drama “Journeyman” showed the biggest percentage jump vs. the “live plus same day” rating (14.3%, 4.07 vs. 3.56), followed closely by CBS drama “Cane” (13.5%, 3.37 vs. 2.97) and Fox’s “K-ville” (13.3%, 2.56 vs. 2.26).

And on a smaller scale, CW saw nice percentage point gains for “Reaper” (17%, 1.74 vs. 1.49) and “Gossip Girl” (12%, 1.27 vs. 1.13).

Also on the rise were returning shows that air in crowded timeslots like “Criminal Minds” on CBS (up 16%, 3.09 vs. 2.60) and “Prison Break” on Fox (up 10%, 3.55 vs. 3.14). And, not surprisingly, Friday shows “Numbers” on CBS (up 19%, 3.09 vs. 2.60) and “Las Vegas” (up 17%, 2.92 vs. 2.49) looked better in the “live plus seven” column.

Versus the “live plus same day” averages for premiere week, NBC, CBS and Fox increased their 18-49 ratings by 0.3 of a point in these newly released “live plus seven” averages, while ABC increased by 0.2 of a point and CW was up 0.1. For premiere week last year, all four major networks went up 0.1 of a point from “live plus same day” to “live plus seven,” while CW was flat.

CBS overtook ABC in average primetime audience for the frame (12.54 million to 12.43m). And NBC edged out ABC for premiere week’s outright 18-49 lead (4.2 to 4.1); of course, the Peacock’s victory already was denoted with an asterisk due to its implementation of a new Nielsen rule allowing it to cume the rating for two airings of “Heroes.”

Overall, the Big Four networks’ premiere-week 18-49 delivery rose by 8% in “live plus seven” vs. the “live plus same day,” reported a couple of weeks ago (15.0 vs. 13.9). CBS points out that in the same week, ad-supported cable as a group rose by just 2% (15.7 vs. 15.4).

According to NBC, 86.4% of the primetime viewing by adults 18-49 on the Big Four during premiere week was live, 6.3% same day and 7.3% between same day and plus seven. This compares with 94.3% live in the fourth quarter of last year, 2.9% same day and 2.9% greater than same day.

‘Grey’s Anatomy’ gained a full point in the 18-49 demo after figuring in its ‘live plus seven’ rating.