Many editions have more than one translation, such as the multilingual editions from Iran. There is also a certain number of popular editions that have only one or a few quatrains in different translations, and last but not least, there are numerous editions that have FitzGerald's version together with others. There are more than one thousand editions of FitzGerald's translation or titles that contain FitzGerald's texts. This variety makes it rather complicated to compose a proper, comprehensive index of translators, and it implies that the list does not strive for completeness.
For practical reasons the index can only list the name, title and year, which is hardly sufficient to identify each specific title in the index. Also for practical reasons FitzGerald's editions are excluded, simply because there are too many.