At least 28% of 40,184 people who tested positive for Covid-19 between January 22 and April 30 in India were asymptomatic, a study conducted by the Indian Council of Medical Research (ICMR) shows, underlining that a large proportion of those tested and found positive were family contacts who did not display symptoms.

from Times of India https://timesofindia.indiatimes.com/india/28-of-covid-patients-asymptomatic-icmr-study/articleshow/76114774.cms