Last night’s Nashville Star American Idol finale did something an Idol finale hasn’t done since 2006: It gained viewers over the previous season-ender. The coronation of country crooner Scotty drew 29.3 million viewers, up a whopping 21 percent from last season’s finale (24.2 million). Idol was also up 12 percent among viewers under 50, averaging a 9.2 rating in the demo (compared to an 8.2 rating in 2010). Last year’s capper, as you’ll recall, featured the sign-off of a bored and disinterested Simon Cowell; as you’ve probably forgotten by now, it also included the announcement that somebody named Lee DeWyze had won the competition. Counting DVR viewing, Fox’s Simon-free Idol looks on track to finish the season up about 5 percent in overall viewership, but down about 5 percent among younger viewers. We’re gonna chalk that up to all the cougar moms tuning in for Steven Tyler this season and declare the Idol reboot a success.