size of Indian work populations in the United States.

Here is some summary data on Indians who work in the United States, which I found at this website. There are roughly 2 million persons of Indian origin in the U. S. today.
About the Asian American Hotel Owners Association
Representing over 8,300 members, AAHOA is one of the leading forces in the hospitality industry and one of the most powerful Asian American advocacy groups. Together, the members own more than 20,000 hotels, which have over one million rooms, representing over 50 percent of the economy lodging properties and nearly 37 percent of all hotel properties in the United States.
Of the hotels owned by AAHOA members, approximately 11,700 are franchised while 6,300 are independent. The market value of the properties owned by AAHOA members is estimated to be $29.9 billion in franchised properties and $8.1 billion in independent properties.
About the American Association of Physicians of Indian Origin
With a constituency of over 41,000 doctors and 10,000 medical students and residents, AAPI is the largest ethnic medical association in the United States and is the largest Indian American professional association in the United States.