original: 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.
simplifications: The amount of C-types may actually be greater than this, because C-types are much darker than most other asteroid types.  D-types and others are only common at the extreme outer edge of the Main Belt. The size of C-types may actually be bigger, because C-types are darker than other asteroid types except D-types. The proportion of C-types may be greater because they are darker than most other asteroids. Except D-types and others common only at the edge of the Main Belt. The amount of C-types may actually be larger than this. C-types are much darker than most other asteroid types. D-types are an exception. The proportion of C-types could be higher. This is because C-types are much darker than most other asteroid types, except D-types and other types found mostly in the outer edge of the Main Belt. The amount of C-types may actually be more than this. This is because C-types are much darker than most other asteroids except D-types and others usually at the most outer edge of the Main Belt. There may be more C-types than this. C-types are darker that most other asteroids and are only found at the outer edge of the Main Belt. The proportion of C-types may be greater than this. This is because C-types are darker than most other asteroid types. D-types and those common at the extreme outer edge of the Main Belt are the only ones darker than C-types. Among the asteroids usually found at the extreme outer edge of the Main Belt, C-types asteroids are much darker than other asteroids (except D-types) and so the proportion stated here may actually be greater. The share of C-types may rise faster than this, because C-types are much darker than most other asteroid types except D-types, and others are common only at the severe outer edge of the Main Belt.