Hello, I am new to this forum and need help with a line chart in Excel.

I have 40 years of annual data, each expressed as a mean with a confidence interval (CI) having an upper limit (UL) and a lower limit (LL). Instead of plotting the data using error bars to show the CI, I wanted to plot 3 smoothed lines on the same chart: all the ULs, all the means, and all the LLs. This was successful, and the resulting chart shows the mean values with the ULs above and the LLs below. So far so good.

The problem is that the entire chart area is white, and so the area between the UL line and the LL line does not show up well. What I need is to SHADE IN the chart area between the UL and the LL to create a "confidence band" around the mean line. (The idea is that this band grows with time, and I want to show its growth.)

I have no idea how to do this, so any advice would be greatly appreciated.

Thanks in advance,
JohnnyCav