The indicators of the mortality table represent a system of age-ordered and interconnected series of numbers, organized as a description of the process of decreasing with age under the influence of the mortality of a certain theoretical generation with a fixed initial number. Mortality tables are built to estimate the "Life Expectancy" indicator.

Life expectancy at birth represents the number of years that, on average, one person from the generation born will live, provided that, throughout the life of this generation, the mortality rate at each age remains the same as in the year for which the indicator is calculated.

The initial statistics for calculating mortality tables are age-specific mortality rates, which are calculated as the ratio of the number of deaths at a given age during a calendar year to the average annual number of people of a given age.

The probability of surviving to the next age "px" is the proportion of people surviving to the end of a given age interval from among those surviving to its beginning.

The life expectancy of those who have reached the age of "x" represents the number of years that those who have reached this age will have to live while maintaining the current level of mortality at each subsequent age.