Like other commenters pointed out, I think it's important to look at the economy of each country. Spain's GDP, for example, heavily relies on tourism (12%, according to official sources [1]), with most of that happening during the summer. Almost no one is traveling to Spain right now, so you could expect almost a 12% drop in GDP. That's a big chunk of the 22% drop you see in the chart.

[1]: https://www.ine.es/dyngs/INEbase/en/operacion.htm?c=estadist...