Examples from Joshua Project (https://joshuaproject.net/), Nov 2023:

• United States:
  • People Groups: 323; Population – 216,195,000
  • Unreached People Groups: 97 (18.6%); Population – 14,397,000 (4.2%)
  • Largest Religion: Christianity (76.6%)
• Brazil:
  • People Groups: 522; Population – 339,720,000
  • Unreached People Groups: 49 (15.2%); Population – 123,000 (0.1%)
  • Largest Religion: Christianity (90.2%)
• Kenya:
  • People Groups: 110; Population – 54,881,000
  • Unreached People Groups: 33 (30.0%); Population – 5,385,000 (9.8%)
  • Largest Religion: Christianity (80.2%)
• Vietnam:
  • People Groups: 119; Population – 98,698,000
  • Unreached People Groups: 68 (57.1%); Population – 9,086,000 (9.2%)
  • Largest Religion: Buddhism (51.5%)
• India:
  • People Groups: 2279; Population – 1,353,748,000
  • Unreached People Groups: 2,048 (89.9%); Population – 1,284,917,000 (94.9%)
  • Largest Religion: Hinduism (80.3%)
• Algeria:
  • People Groups: 38; Population – 45,521,000
  • Unreached People Groups: 34 (89.5%); Population – 45,487,000 (99.9%)
  • Largest Religion: Islam (96.5%)
• Israel: 
  • People Groups: 48; Population – 9,076,000
  • Unreached People Groups: 37 (77.1%); Population – 8,803,000 (97.0%)
  • Largest Religion: Ethnic Religions (75.8%)
• Iran:People Groups: 94; Population – 88,861,000
  • Unreached People Groups: 84 (89.4%); Population – 88,512,000 (99.6%)
  • Largest Religion: Islam (97.8%)
• Germany:
  • People Groups: 94; Population – 83,102,000
  • Unreached People Groups: 27 (28.7%); Population – 5,090,000 (6.1%)
  • Largest Religion: Christianity (62.2%)
• Russia:
  • People Groups: 182; Population – 143,594,000
  • Unreached People Groups: 115 (63.2%); Population – 17,775,000 (12.4%)
  • Largest Religion: Christianity (57.2%)
• China:
  • People Groups: 545; Population – 1,408,222,000
  • Unreached People Groups: 441 (80.9%); Population – 140,553,000 (10.0%)
  • Largest Religion: Non-Religious – Communism (44.5%)