Page de garde, graph "listing duration"
Pour listing duration:
sur l'image : "XXXX titres cotés entre 1797 et 1952" (XXXX étant le nombre total de lignes du graphique)
le titre pourrait être plus précisément : "listing duration for securities listed on the official stock exchange"
et la légende : This graph draws for each security a line starting the year it was first listed and ending the year it disappeared from the official list. For a number of securities, the last date is not known yet and the line ends in 1952, last date for which all the prices are already in the database.