Here’s some timelines:
Diablo → Diablo II: 3 years
→ Diablo III: 12 years
→ Diablo IV: 11 years
Elder Scrolls I → Elder Scrolls II: 2 years
→ Elder Scrolls III: 6 years
→ Elder Scrolls IV: 4 years
→ Elder Scrolls V: 5 years
→ Elder Scrolls VI: est. 15+ years
GTA I → GTA II: 2 years
→ GTA III: 2 years
→ GTA IV: 7 yeras
→ GTA V: 5 years
→ GTA VI: est. 12+ years