Rolling average versus actual values

Using rolling 5-year averages on a line chart instead of (or alongside) actual yearly totals helps in several ways:

1. Smooths Out Volatility – Annual data can fluctuate due to short-term events, outliers, or noise. A rolling average evens out these fluctuations, making long-term trends more visible.
2. Reveals Underlying Trends – By reducing the impact of short-term anomalies, a rolling average highlights whether values are generally increasing, decreasing, or staying stable over time.
3. Reduces Impact of Outliers – A single extreme year won’t dramatically affect the trend, making the visualization more reliable for decision-making.
4. Better for Forecasting & Planning – Since rolling averages remove erratic swings, they help in making more informed predictions about future performance.
5. Comparability Across Periods – If data is seasonal or cyclical (e.g., sales, weather patterns, economic trends), rolling averages allow for better year-over-year comparisons without being skewed by short-term peaks or dips.

That said, using actual totals by year is still important for seeing precise data points and sudden shifts. Many charts use both together—totals as bars or markers and the rolling average as a smoother line.