I found the Weight Watcher's point range on the United States Patent and Trademark Office's website. [link to Weight Watcher's point patent] Here are the point ranges:

Less than 150 pounds
18-25
150 to 174 pounds
20-27
175 to 199 pounds
22-29
200 to 224 pounds
24-31
225 to 250 pounds
26-33
Over 250 pounds
28-35