Time Series
Time series are sequences of statistical indicators arranged in chronological order, which characterize the development of a phenomenon over time. Time series may consist of absolute, relative, and average values. Depending on the nature of the studied phenomenon, time series are divided into momentary and interval series. Momentary time series reflect the state of studied phenomena at specific points in time. In medical-demographic research, for example, this is total disability (number of disabled persons as of 01.01). Interval time series consist of interval values and reflect the results of the development of studied phenomena over separate periods of time. In medical-demographic research, for example, this is primary morbidity (the number of newly identified cases during a year).
Source: Order of Rosпотребнадзор dated 20.09.2010 No. 341
"On approval of Methodological Recommendations for Social-Hygienic Monitoring"