Only issues 1 to 11, 13 to 23, 25 to 28, 58 to 73 were collected.
Not all in chronological trades either. So 32 or so issues are unaccounted for.
Which means that some characters show up without explanation as their stories are collected, a gun-fu guy called Alpha shows up in the last trade and refers to a story that isn't in one of the trades for example.