Average price on market

Good morning,

When looking at the average price on the market and I go and see what it looks like on the market, it's a lot different. There is probably a reason for that but average price right now does not show the average price on the current market. Maybe it shows the average price the resource was sold in the past? If it's the case, it's still a valuable information, I just want to make sure there is no mistake in the calculation.

Thanks,