I made a skin chart with all champions and some data about their

Champions and their skins since 2019 : r/LeagueOfMemes

Drug discovery - Wikipedia

India Medals In Olympics 2021: India finishes 48th, best in four decades; 33rd in terms of overall medals won

All Ultimate Skins in League of Legends

SZA's Ruination Brought Her Everything - The New York Times

A graph of average days per skin, updated to patch 13.20 : r/leagueoflegends

A graph of average days per skin, updated to patch 13.15 : r/leagueoflegends

Arcane Jinx and Vi In-Game Skin Models in Wild Rift Leaked by Dataminers

An analysis on the question whether Riot buffs champions which get a new skin (with quite some graphs, data available from webscraping patch notes and leagueofgraphs if you want to do your