US force of mortality over time

From "Modeling Longevity Risk Using Consistent Dynamics Affinee Mortality Models" by Islem and Bedoui Univ. of Sousse - Laboratory Research for Economy, Management and Quantitative Finance

"Figure.1 shows the plot of the average force of mortality given by m[bar](t,T) for population aged between 50 and 100 for the years 1933-2010. we use this mortality curve data to represent the model fitting. We can see through this figure the exponential shape of the mortality curve and the improvement in mortality over the periode of the study , this improvements have appeared at various rates for different ages."