The chart illustrates the adoption of different versions of the International Classification of Diseases (ICD) by countries from 1950 to 2022. Initially, the ICD-7 was the only version in use, with a gradual increase in adoption until the late 1970s. The transition to ICD-8 began in the mid-1970s, overlapping with ICD-7, and peaked in the early 1990s. Subsequently, ICD-9 was introduced in the late 1980s, quickly becoming the dominant classification by the early 2000s. The most recent version, ICD-10, started gaining traction in the early 2000s and has been the primary classification system since 2010. The data reveals a clear pattern of gradual transition from one version to the next, with overlapping periods where multiple versions were in use. This reflects the time needed for countries to update their systems and adopt new guidelines. The chart also highlights the lag in reporting, as noted in the data source, which may affect the apparent decline in recent years. Overall, the chart provides a comprehensive view of how countries have progressively adopted updated ICD guidelines, ensuring consistency in classifying causes of death worldwide.