From what can be told from these pictures, the density of the negatives seems to be in the normal range. However, as others have already indicated, it appears there are some darker zones along the area of the perforation and this area normally should be perfectly clear base. In your case this was either fogged by a light leak or it is retained silver halide caused by underfixing (exhausted fixer, lack of agitation, too low temperature ...). Developed silver from a light leak appears black if you look straight at the surface of the film (without twisting it). Retained silver halide from insufficient fixing will usually have a more milky appearance. If unsure you could simply try a refix with fresh fixer and see if the film clears.