Close your eyes, take a deep breath of lavender and citrus oils, and allow the flute music to soothe your soul. As a massage therapist's hands knead the knots out of your back, you relax into a deeper and more tranquil state. Pretty soon, you're on the verge of sleep. As you slip into dreamtime, your mind visits a funny place indeed. It is the health spa of 1984. All around you, wealthy women lounge about sipping tea, nibbling low-calorie food, and indulging in treatments such as manicures, facials and massages. The country-club setting is quite exclusive. The pampered ones, pretty in their pink workout jumpsuits, are discussing the latest episodes of Dallas and Dynasty. When the massage therapist whispers in your ear, you awake from the dream. Lo and behold, you're in the Modem Spa of 2004. A warm feeling washes over you, and you smile. Reality is going to be better than the dream. Today's health spa is no longer for the super-wealthy. It's gone mainstream, and the variety of treatments is mind-boggling. The spa industry has expanded like a sponge left soaking in a honey-papaya enzyme bath. The United States now boasts more than 12,000 spas, up from 1,374 in 1990. The International SPA Association reports that 45 million Americans visited spas from June 2002 to June 2003. 'Today spas are like Starbucks. They are everywhere. There is a flavor for every taste,' said Melinda Minton, founder of The Spa Association, the largest of its kind in North America. Joining the original destination and resort spas are fitness-club spas, medical spas, adventure spas and holistic spas. Spa Finder, a travel and marketing company that publishes Spa Finder magazine, now lists 30 special-interest categories on its Web site. The connoisseur can select from budget spas, beach spas, eco-spas, Pilates spas, spirituality spas, stop-smoking spas, vegetarian spas, yoga spas ... the list goes on. Pressed for time? America now boasts 8,734 day spas where you can slip in for a quick treatment. According to the passage, what is the most obvious difference between the spas in 1984 and that in 2002 ?