1 Although any individual may develop a case of pinworms, the infection occurs most frequently in school children between 5 to 10 years of age.  Pinworm infections occur in all socioeconomic groups; however, human-to-human spread is favored by close, crowded living conditions. Spread among family members is common.
Before they start collecting, stamp collectors try to identify the types of stamps. These will help them segregate and sort stamps according to their classification. On its basic concept, there are three main classifications of stamps â special, commemorative, and definitive.
How Many Stamps Are There in a Book of Stamp? A regular book of stamps from the U.S. Postal Service contains 20 individual stamps. In January 2014, first-class postage letter (1 oz.) rates were increased but the stamps count remained same. Additional Information: