Table 1.

Parameters used in a life table.

Parameter	Definition	Equation
$d_x$	Number of dogs dying in the year interval [x, x + 1)
$l_x$	Number of dogs living at year x ($n$ denotes the starting point for the final year interval)	${\sum }_{i=x}^n{d}_i$
${\widehat{q}}_x$	Probability of dogs dying in the year interval [x, x + 1)	${\widehat{q}}_x=d_x/l_x$
${\widehat{a}}_x$	Mean fraction of last year of life lived by dogs died in the year interval [x, x + 1)	${\widehat{a}}_x=\frac{\sum ({\mathit{lifespan}}^{\ast }-x)}{d_x}$
$L_x$	Number of dog-years lived in the year interval [x, x + 1)	$L_x={(l}_x-d_x)+{\widehat{a}}_x\ast d_x$
$T_x$	Number of dog-years lived beyond year x	${\sum }_{i=x}^n{L}_i$
${\widehat{e}}_x$	Life expectancy at year x	${\widehat{e}}_x=T_x/l_x$

*Lifespan of dogs dying in the year interval [x, x + 1).