15.    Concentrations of Risk

The Company’s revenues are concentrated in a small group of customers with some individually having more than 10% of total revenues.

Revenues from three customers that exceeded 10% of total revenues for the three months ended March 31, 2022 were 52%, 12%, and 12%. The accounts receivable from the top three customers were 0%, 0%, and 40% as well as 16% and 22% from two other customers of the total accounts receivable as of March 31, 2022.

Revenues from three customers that exceeded 10% of total revenues for the three months ended March 31, 2021 were 28%, 24%, and 16%. The accounts receivable from the top three customers were 13%, 0%, and 44% as well as 25% from one other customer of the total accounts receivable as of March 31, 2021

The Company’s financial instruments that are exposed to concentrations of credit risk consist primarily of cash. Cash balances are maintained principally at major U.S. financial institutions and are insured by the Federal Deposit Insurance Corporation (“FDIC”) up to regulatory limits. Such cash balances are currently in excess of the FDIC insurance limit of $250,000. As of March 31, 2022, the total amount exceeding such limit was $10,270,000. The Company has not experienced any credit losses associated with its cash balances in the past.