There have been massive declines in violence as people have learnt to co-operate with those who are not like themselves, and with those who are like themselves, but disagree.
Wikipedia lists the places that have ongoing armed conflicts.
Four have had more than 10,000 deaths in the last year (start date):
Afhghanistan (1978); Iraq (2003); Nigeria/Cameroon/Niger/Chad - Boko Haram (2009); Syria (2011).
1,000 - 9,999 deaths
Turkey-Iraq, Somalia-Kenya; Pakistan; Mexico; Libya; Yemen-Saudi Arabia; Egypt; Sudan; South Sudan-Ethiopia; Ukraine
100 - 999 deaths
India-Pakistan; Pakistan-Iran; Myanmar; Thailand; India; Israel-Palestine; Colombia; India; Philippines; Armenia-Azerbaijan; China; Ethiopia; DR Congo; Nigeria; Algeria-Tunisia; Sudan; DR Congo-Burundi; Russia; Central African Republic; Mali; Egypt; Burundi; Turkey