Thus far little is known about longer-term trends of descriptive youth representation in legislatures, especially in non-Western and non-democratic countries. In response, this chapter presents the new Global Youth Representatives Age (GYRA) dataset documenting young adult representation in national parliaments covering 953 sessions of 253 legislative chambers for 181 countries over the period from 1971 to 2023. The chapter introduces the dataset and provides a descriptive-exploratory historical analysis of major trends in youth descriptive representation over the past five decades. Empirically identifying longitudinal patterns of persistent absence, decreasing representation, increasing representation, and persistent presence, it documents differing trends across world regions. Most notably, there have been severe declines in youth representation in Asia and in the Global South, but stable or even increasing youth representation in parts of continental western and northern Europe. I conclude by offering four propositions concerning historical changes in parliamentary youth representation worth testing in future research.