You're listing pretty much all the wars of that era.

That adds up to about 5 years or less at war for almost all European countries. Probably the most peaceful century in the history of Europe.

During this time, European population also doubled, life expectancy increased by 10-15 years, and GDP/person more than doubled.

That's not true. Here's an abbreviated list from:

http://historyguy.com/major_wars_19th_century.htm

I'm sure there are others. It lists:

  Greek War of Independence (1821-1832)
  French invasion of Spain (1823)
  Russo-Persian War (1826-1828)
  Russo-Turkish War (1828-1829)
  Hungarian Revolution and War of Independence (1848-1849)
  First Schleswig War (1848-1851)
  Wars of Italian Independence (1848–1866)
  Crimean War (1854–1856)
  Second Schleswig War (1864)
  Austro-Prussian War (1866)
  Franco-Prussian War (1870-1871)
  Russo–Turkish War (1877–1878)
  Serbo-Bulgarian War (1885)
  Greco–Turkish War (1897)
Together, that adds up to multiple decades of war.

I think https://ourworldindata.org/grapher/deaths-in-wars-project-ma... puts this in perspective. The period from 1815 to 1915 was a much more peaceful period measured by deaths in war than 1915 to 2015, though 1975 forward seems like a return to that level (but world population is so much larger now that it's even better than it seems).

We're talking about different things.

Counting the years when there was a war anywhere is Europe, you'll end up with a large number.

I'm counting how often each country was at war. Several countries had no wars, and even the most war torn country didn't fight for more than 10-15 years.

That's really not true if you look at the European neighbors and European territories of Russia and the Ottoman Empire.

Also not true of Spain, which spent a lot of time in internal warfare (with occasional outside interventions.)

But, yes, excluding those, most of the countries in Europe were too busy fighting endless wars throughout their (or their allies’ or enemies’) colonial empires (whether to expand them, defend them, or put down or assist rebellions in them) to bother fighting other powers in Europe in that period.

I've listed most of the conflicts that occurred on the European continent (I've omitted several Russian wars, and there's a couple more civil wars I've also omitted). And some of that is because I'm doing wildcards rather than trying to, e.g., track down every single Balkan conflict in the 19th century.

If you think I've included most of the conflicts that involved European powers on one side... no. Not even close. This is an era when Europeans are essentially in a permanent state of war with everybody they consider inferior to themselves. And, albeit at the tale end of this era, it's still the era when private companies assert the right to go to war against other people. Don't forget that non-European wars can still leave indelible imprints on the European psyche--the Boer War and the Russo-Japanese War both had massive implications for their home countries, and it's ultimately the Italian invasion of Libya that kicks off World War I.

> Probably the most peaceful century in the history of Europe.

World War II is not yet 100 years gone, but there's not really going to be any question that that the 100 years after WWII will be the most peaceful 100 years in recorded history. For comparison's sake, you're probably looking at like roughly a Napoleonic Wars' amount of death in conflict on the European continent between the Napoleonic Wars and WWI. And as I've mentioned, you're really lucking out that there's just under 100 years between two of the bloodiest conflicts of European history, so you get to pick a 100 year time period without the largest conflicts. If the time period were instead 110 years, now you'd have to confront the bloodbath not only of WWI but also the Russian Civil War.