Task: Text Simplification
Input (English): the proportion of c-types may actually be greater than this , because c-types are much darker than most other asteroid types except d-types and others common only at the extreme outer edge of the main belt.
Output (English): the ratio of c-types may really be more than this , because c-types are much darker than other minorl planet types , not counting d-types and others common only at the most outer edge of the main belt.