This page fetches live data at runtime with JavaScript, and so browsing LOCALLY in requires viewing via the "live server" approach -- in order to fully reflect the page's data display. Note: the 1551 and Decade toggle buttons additionally need a server that runs nyc/five_server_middleware.js -- confirmed working via the "Live Server (Five Server)" VS Code extension (yandeu.five-server) with fiveserver.config.js at the project root (verified 2026-08-28). Running serve_local.py directly from the nyc folder also still works as a standalone alternative. VS Code's original "Live Server" extension (ritwickdey) alone cannot handle those buttons' save requests.