There are approximately 452,000,000 Spanish speakers world wide.
According to the Census Bureau 2008 data, nearly 1 in 6 Americans, or 46.9 million people, are Latino. Even more importantly for chlidren’s librarians, 44% of children under the age of 18, and 47% of children under 5 are Latino. (Census factfinder)
There are 20 countries that have Spanish as an official language, and at least 4 other countries where Spanish is also an important language.
According to the “Serving Non-English Speakers in U.S. Public Libraries” study conducted in 2008, approximately 78% of public libraries in the United States offer some sort of services in Spanish. (For more information, you can find the survey here)