As a lien buyer, when can I apply for tax deed?

The holder of a tax certificate at any time after 2 years have elapsed since April 1 of the year of issuance of the tax certificate and before the cancellation of the certificate, may file the certificate and an application for a tax deed with the tax collector of the county where the property described in the certificate is located. The tax collector may charge a tax deed application fee of $75. Seven years after the date of issuance of a tax certificate, if a tax deed has not been applied for, and no other administrative or legal proceeding, including a bankruptcy, has existed of record, the tax certificate is null and void and shall be canceled.