In the 10 years I've been into vipers, I've only seen 3 unknown vipers in the UK outside club events, a RT in Monaco and a couple of snakes at N'burg, have never seen a viper yet in my trips to the US, except VOI and ViperDays which was an eye opener
here's some interesting figures posted a couple of weeks ago:
VCA Region Count Zone July 2005
Japan 22 ASIA
Germany 58 EUR
Switzerland 86 EUR
United Kingdom 26 EUR
Gateway 67 MW
Illinois 283 MW
Indiana / Kentucky 137 MW
Kansas City 117 MW
Motor City 199 MW
Ohio 162 MW
Ontario, Canada 54 MW
Minnesota 73 MW
National 47 MW
New England 114 NE
New Jersey 177 NE
New York / CT 245 NE
Quebec, Canada 48 NE
Virginia / Maryland 171 NE
WV / PA 119 NE
Alabama / Tennessee 76 SE
AR / LA / MS 76 SE
Carolinas 106 SE
Cen. - No. Florida 204 SE
Georgia 87 SE
South Florida 187 SE
Colorado / Utah 96 SW
Houston 82 SW
New Mexico 33 SW
North Central Texas 153 SW
Oklahoma 31 SW
South Central Texas 65 SW
Arizona 109 W
Central California 100 W
Nevada 71 W
Northern California 198 W
Oregon 58 W
Southern California 383 W
Washington 87 W
Western Canada 34 W
Total 4441