Question: How many equestrians were surveyed in Oregon, Washington, and Idaho?
About the article "Equestrianism", section "Health issues".

Candidate passages:
Handling, riding, and driving horses has a number of health risks.
Riding has some inherent risks, as when mounted, the rider's head may be up to from the ground, and the horse may travel at a speed of up to .
The injuries observed range from very minor injuries to fatalities.
A recent study in Germany reported that the relative risk of injury from riding a horse, compared to riding a bicycle, was 9 times higher for adolescents and 5.6 times higher for younger children, but that riding a horse was less risky than riding a moped.
In Victoria, Australia, a search of state records found that equestrian sports had the third highest incidence of serious injury, after motor sports and power boating.
In Greece, an analysis of a national registry estimated the incidence of equestrian injury to be 21 per 100,000 person-years for farming and equestrian sports combined, and 160 times higher for horse racing personnel.
Other findings were that use of spurs may contribute to ankle fractures and dislocations, and helmets likely prevent traumatic brain injuries.
In the United States each year an estimated 30 million people ride horses, resulting in 50,000 emergency room visits (1 visit per 600 riders per year).
A survey of 679 equestrians in Oregon, Washington, and Idaho estimated that at some time in their equestrian career one in five will be seriously injured, resulting in hospitalization, surgery, or long-term disability.
Among survey respondents, novice equestrians had an incidence of any injury that was threefold over intermediates, fivefold over advanced equestrians, and nearly eightfold over professionals.
Approximately 100 hours of experience are required to achieve a substantial decline in the risk of injury.
The survey authors conclude that efforts to prevent equestrian injury should focus on novice equestrians.
Fossil specimens were found from western Washington and Oregon in the northwest, south to Southern California and southeast Arizona, to Idaho, Nebraska, Oklahoma and four areas of Florida. 
"Punctum randolphi" is found in North America, in British Columbia, Washington, Oregon, and Idaho. 
Frontier Communications Northwest was founded in 1964 as the General Telephone Company of the Northwest, Inc. and later became GTE Northwest, IncorporatedGTE Northwest originally served Idaho, Montana, Oregon, Washington.
In 1993, GTE acquired Continental Telephone (ConTel); as a result, ConTel operations in Oregon, Washington, and Idaho were merged into GTE Northwest.
In 1994, GTE sold ConTel of Idaho to Citizens Communications (which later became Frontier Communications).
In 1995, GTE sold operations in Montana to Citizens Communications, and absorbed ConTel of Oregon into GTE's existing Oregon operations.
In 2000, Bell Atlantic acquired GTE, forming Verizon.
As a result, GTE Northwest was renamed "Verizon Northwest, Inc." It continued to provide local telephone service to former GTE regions and some ConTel regions in Idaho, Washington, and Oregon. 
The Intermediate Province is located in parts of Washington, Oregon and Idaho.