ISO/IEC 8859 Usage Statistics

ISO 8859, more formally ISO/IEC 8859, is a joint ISO and IEC standard for 8-bit character encodings for use by computers. The standard is divided into numbered, separately published parts, such as ISO/IEC 8859-1, ISO/IEC 8859-2, etc., each of which may be informally referred to as a standard in itself. There are currently 15 parts as of 2006 excluding the abandoned ISO/IEC 8859-12 standard.

http://en.wikipedia.org/wiki/ISO_8859

Document Encoding