Create publication-quality data visualizations for [DATASET/TOPIC].
Data: [DESCRIBE OR PASTE SAMPLE DATA]
Audience: [EXECUTIVE / TECHNICAL / PUBLIC / ACADEMIC]
Tool: [MATPLOTLIB / SEABORN / PLOTLY / ALTAIR]
Provide complete Python code for:
1. **Distribution Plot**: Histogram or density plot of key variable
2. **Trend Line**: Time series with annotations for key events
3. **Comparison Chart**: Bar or grouped chart comparing categories
4. **Correlation Matrix**: Heatmap of variable relationships
5. **Dashboard Layout**: Multi-chart figure combining 4 key views
For each visualization:
- Clean, readable code with comments
- Professional styling (custom colors, proper labels, no chart junk)
- Title, subtitle, axis labels, legend, and source note
- Export-ready (300 DPI PNG or SVG)