−1−0.9−0.8−0.7−0.6−0.5−0.4−0.3−0.2−0.100.10.20.30.40.50.60.70.80.911880188518901895190019051910191519201925193019351940194519501955196019651970197519801985199019952000200520102015
Mean
0.99