PoPStat-COVID19: Leveraging Population Pyramids to Quantify Demographic Vulnerability to COVID-19. - Buddhi Wijenayake; Athulya Ratnayake; Lelumi Edirisinghe; Uditha Wijeratne; Tharaka Fonseka; Roshan Indika Godaliyadda; Samath Dharmaratne; Parakrama Ekanayake; Vijitha R. Herath; Insoha Alwis; Supun S. Manathunga (CoRR, 2025)