As television executives make their way to New York to promote a new fall lineup —<br />and ask themselves questions like “Will we find our own ‘This Is Us’ next year?” and “What’s the next old show we should revive?” — they are also starting to take stock of the season that is just wrapping up.<br />As 21st Century Fox’s executive chairman, Lachlan Murdoch, told investors last week, the performance at the network has been “frustrating for us all.”<br />And ABC — weathering another season without a hit while watching old franchises limp along — will finish last among 18-to-49-year-olds for the second consecutive year.<br />And this was a year when several returning juggernauts across all networks — shows like “The Voice,” “Modern Family”<br />and “NCIS” — all had rating drops of 15 to 19 percent among adults under 50.