50 million to 70 million — Estimated number of Americans with a sleep disorder.

6 hours, 40 minutes — Average length of time adults report sleeping per night.

230 million — Filled prescriptions of sleeping medication Ambien and Ambien CR since it was introduced in the U.S. in 1992.

1 in 5 — Car accidents associated with driver sleepiness.

59% — Adults report snoring, which can be a symptom of sleep apnea.

300% — Approximate increase in stroke risk for men with moderate to severe obstructive sleep apnea.

17 to 19 hours — When you're awake this long, your performance behind the wheel is worse than drivers with a blood alcohol level of 0.05 percent.

450 to 700 hours — The amount of sleep parents of new babies lose in the first year.

$20 billion — Estimated annual value of the sleep industry, from aromatherapy pillows to high tech beds and sleep aids.

1879 — Year Thomas Edison produced a reliable light that could be used in homes. The light artificially extended the day and, some experts say, cut into our zzz's.

Sources: Institute of Medicine, National Sleep Foundation, Sanofi-Aventis U.S., Occupational and Environmental Medicine, Australia's National Sleep Research Project