Why has the percentage of CEOs of Indian descent gone up in the last decade ?
In the last decade there is a growing trend of corporations being led by CEOs of Indian descent.  Many factors have contributed to this trend including but not limited to:

1) Immigration laws that attract best of talent from across the world to western nations
2) Strong education system in India
3) English as the primary/secondary language in most educational institutions across India
4) Cultural diversity of India that fosters empathy and adaptability
6) Immigrant's drive to succeed in a foreign nation given limited safety net
7) Acceptance of cultural and social diversity in large enterprises