Small multiple bar charts with tooltips
Small multiple bar charts show two text-analysis measures, Analytic and Continental, across four categories: self mentions, words per sentence, STTR, and directives. Each chart uses horizontal bars to display percentages, with a color scale from red to blue mapping value magnitude. The visualization, built with D3 v3, loads data from a TSV file and nests it by country. Hovering over a bar triggers a tooltip via the `d3.tip` library, revealing the exact country, year, and percentage value.