The CW may be experiencing a little bit of the sophomore season blues when it came to its big hit last season, "Vampire Diaries."

The series -- starring Nina Dobrev, Paul Wesley and Ian Somerhalder -- premiered its second season Thursday with a 2.0 rating/3 share, in Fast National overnight ratings from The Nielsen Co. That was down more than 35 percent from its series premiere the year before, where it earned a 3.1/5, on its way to becoming The CW's top-rated show of the season.

It's not exactly fair to compare the second season premiere of a show to a series premiere, especially since the very first episode of many television shows are artificially inflated because of a larger group of people trying a new program out. In fact, "Vampire Diaries" seems to be in-line with the audience it basically ended its first season with. "Vampire Diaries" averaged a 2.5 household rating through its first 10 episodes, including the series premiere, but closed out with a 2.1 household rating in its remaining 12 episodes, including a series finale that earned a 2.1/4.

The season premiere matches the audiences gained on April 8, April 22 and May 6, but is not a series low. That came April 1 when the series could only manage a 1.7/3, 26 percent off its season average.

The most recent episode also will not end up the top-rated show of the week for The CW, a title it held for nearly every new episode it aired last year. That honor this week instead goes to the new series "Nikita," which built on its "Vampire Diaries" lead-in to finish with a 2.2/3, slightly better than the season premiere of "Supernatural" a year before in the same timeslot, which earned a 2.1/3, but was 32 percent off its "Vampire Diaries" lead-in.

Don't fear too much (kind of an ironic thing to say on this site, yes?) The CW is kicking off its season virtually ahead of all the other networks, and it's likely many viewers were not even aware fall programming is yet available. As other networks roll out new episodes, and viewers get used to being in front of their TVs again on weeknights, there is a chance that "Vampire Diaries" audience could remain stable and not fall off, or maybe even grow a bit closer to the 2.3 household rating it averaged last year.

The CW finished the night with a 2.1/3, good for last place behind Fox, whose reruns gave it a 2.3/4.

Fast Nationals usually provide a snapshot of what Americans are watching by pulling numbers from the top urban markets that include both live viewing and same-day timeshifted viewing. A rating point generally represents more than 1.1 million households while the share indicates the percentage of televisions turned on that was tuned to the specific program. These numbers typically shift when final ratings are issued.

Data collected from The Nielsen Co., as distributed by Zap2it. BlipNetwork tracks non-news, non-event programming, and figures for this story reflect airing of new episodes only. For more information on the Audience Loyalty Index, click here.