Why it's larger than 100%? What is the meaning of this number?
This can occur due to discrepancies in institutional reporting.
Let's say that XYZ Company has 20 million shares outstanding and Institution A owns all 20 million. In a shorting transaction, Institution B borrows 5 million of these shares from Institution A and sells them to Institution C. If both A and C claim ownership of the shares shorted by B, the institutional ownership of XYZ could be reported as 25 million shares (20 + 5), or 125% (25/20)
Regardless, a reported institutional owernship percentage of above 100 is very likely to have a extremely high rate of actual institutional ownership.