Hyphenation in compound words

I found compounds.txt file in LT directory. It is case sensitive. Any reason behind case senstivity in this hyphenation. If yes, Is there any way to give case insensitive in compound.txt file for specific words.
E.g. I have fifty five apples. Fifty five apples are there.
First “fifty five” is captured and suggested to hyphenate the term.
But the second occurence is not captured.