Sorry but I don't seem to find any backing for this graph from there. Also any other source found seems to disagree with that chart, see for example nostr:nevent1qqsvwzfuela9ar5lf4y7pqnyryaz2fj8la69cyu5snz0g29pr47upjspzamhxue69uhhyetvv9ujuurjd9kkzmpwdejhgtczyzq6cv7fmvgywu2r95wz2cqn7vjj5wng5jv9etactfva486nvn8kjqcyqqqqqqg3l09rv