Complex sentence: Between 1970 and 2010, overall German road fatalities decreased by almost 80%; from 19,193 to 3,648; over the same time-period, Autobahn deaths decreased from 945 to 430 deaths.
Split into simpler sentences: Between 1970 and 2010, overall German road fatalities had decreased by almost 80%, from 19,193 to 3,648. Over the same time-period, Autobahn deaths decreased from 945 to 430 deaths.