Improvements
\ɪmˈpruvmənts\
The trend of people living longer over time due to declining death rates at certain (or all) ages. Mortality improvements are often expressed as a percentage, either in the form of an annual improvement rate or a reduction facto, i.e., mortality rates improved (reduced) by 5% since last year or current year mortality is equal to 95% of the previous years' mortality.
Mortality improvements are used to project mortality rates in future years when calculating cohort life expectancy.