Get % Distribution Of Invalid Data?

We've got the requirement where we need to load data (usually dirty of course) from a flat file, and for every column, if the value is invalid, I'm putting a -1 in the field as it flows through the data stream - no problem. (I'm converting all invalids to -1 so they'll go into my eventual int column)



My question though is - at the end of the data flow, is there any smooth way to capture the % invalid values in each column. An example: If my table is as follows...where the # 1 signifies "clean data" and -1 signifies dirty.



col1 col2 col3 col4

1 1 1 1

1 -1 -1 1

-1 1 -1 1

-1 1 -1 1



I would want my % distribution query/ssis result to return:



col1 col2 col3 col4

.5 .25 .75 0



I do not want to do a select/ssis process for each column. Any way to do this all in one shot?