Your TunkRank score ranges from 1 (least influential) to 100 (most influential). It is a comparative range, with the most influential twitter user always being 100. The score is on a log-scale, so for every seven (7) TunkRank points or so, the difference in influence doubles. You can read more about the scoring system in this blog post.
You can also look at the raw TunkRank score which is the direct output of the TunkRank algorithm. Raw TunkRank scores can be directly compared to each other, so for example, a person with a score twice as great is twice as influential.