These scrolls and scroll fragments are significant for a couple of reasons. First, all thirty-nine books of the Hebrew Bible are represented, at least in part, except for Esther and maybe Nehemiah (though Nehemiah might be combined with Ezra). Before these discoveries, the oldest Hebrew Bible manuscripts in such complete condition dated to about 1000 C.E. The Dead Sea Scrolls predate that by about a thousand years, dating to the last century B.C.E. at least. Second, the Dead Sea Scrolls are crucial to understanding how the Old Testament was passed down through the years. After studying the Dead Sea Scrolls and comparing them with their younger counterparts, scholars determined that content was passed down with meticulous attention to detail, there being few differences and alterations in the texts. A few of the scrolls, however, suffered greatly from the deleterious effects of time and temperature. As a result, they survive in such fragmentary form that they are unreadable.