The Times paints a troubling picture of new restaurants trying to make it in a bad economy. At Vermilion, which opened in midtown in November, needs annual revenues of at least $6 million to stay open. On a recent weekday evening, the restaurant served 170 covers during lunch and dinner, but owner Robin Dey says they need to serve twice that amount to stay open. Things are a little less stressed at Corton, where good reviews and a good pedigree are driving diners through the door. But owner Drew Nieporent admits that, had he known the dismal state of the economy, he may not have opened. Lucky for diners, he couldn’t see the future.