Figure 1:  
Bulgarian mortality rates for males and females in 1992–93. / Malefemale mortality ratio and lifetable aging rate (LAR) for males and females in Bulgaria in 1992–93.

Figure 2:  
Typical pattern of mortality rates implied by a Gompertz model with and without unobserved heterogeneity. / Lifetable aging rate in a Gompertz model with and without unobserved heterogeneity.

Figure 3:  
Observed mortality rates implied by the modified DeMoivre hazard function for different degrees of heterogeneity in the population.

Figure 4:  
Application of modified DeMoivre hazard functions with Gamma distributed relative frailty to Bulgarian mortality pattern.

Figure 5:  
Comparison of a piecewiseconstant hazard model with unobserved frailty with the modified DeMoivre model with unobserved frailty.

Figure 6:  
Sensitivity analysis of the parameter estimates obtained for Models 1 and 2 in Table 1 with respect to different values of w
