Complex sentence: Since the 1973 oil crisis, France's economy, while still faring well under François Mitterrand and Jacques Chirac, slowed down its explosive growth, thus the mid- 1970s mark the end of the period.
Split into simpler sentences: Since the 1973 oil crisis, France's economy, while still faring well under François Mitterrand and Jacques Chirac, slowed down its explosive growth. Thus, the mid- 1970s mark the end of the period.