violinplot: How to give each violin the same total area?

[EwoutH]

I have a dataset with the weight and fuel type of cars. I would like to (so the total area of 2004 is the same as 2005, as 2006, etc.).

This way, you should be able to observe both the increase in weight (shift upwards over the years) and the move to electric cars (shift from blue to orange). I got quite far with:

sns.violinplot(data=data_clean, x="Year", y="Massa rijklaar", hue="Brandstof klasse", ax=ax, split=True, inner="quartile", linewidth=1, density_norm="count", common_norm=False)

However, my dataset is a bit biased, since not all data is available for cars in older years. So I would like to normalize the area of each violin plot, so that the total area of each plot is the same.

I can't seem to get that to work. I tried most combinations, already, the closest two are here:

density_norm="count", common_norm=True:

density_norm="count", common_norm=False:

density_norm="area", common_norm=True:

density_norm="area", common_norm=False: