Complex sentence: There were approximately 17,000 at-risk Vietnamese on Embassy rolls, which using an average of seven dependents per family meant that the number requiring evacuation was 119,000 and taken with other categories of Vietnamese the number quickly increased to over 200,000.
Split into simpler sentences: There were approximately 17,000 at-risk Vietnamese on embassy rolls, which, using an average of seven dependents per family, meant that the number requiring evacuation was 119,000. Taken with other categories of Vietnamese, the number quickly increased to over 200,000.