Schedule B line 16 is a pre-populated amount – please see the PDF of this schedule here https://bit.ly/2Fxe543

Please note: The credit for persons living alone is based on family income, entered on line 14 of Schedule B. Therefore, if your family income exceeds the amount on line 16 of Schedule B, your credit may be reduced or even nil.

More information here if needed - https://bit.ly/2uq5Ss3