The list is based on a computerized search of 97,565 distinct words, which were mentioned 743,842,922,321 times across the text of Google Books. To give you some idea how comprehensive this is, the most common word was found over 53 BILLION times, and #300 was found a mere 224 million times. Just the list of words found more than 100,000 times is over 1.5 megabytes. NOTE: Unlike most such lists, this one includes proper nouns (marked with *) such as cities or person's names. It also include some abbreviations and single letters.