The following table presents the provision for income taxes and our effective tax rate for the three months ended March 31, 2019 and 2018:

The effective income tax rate on operations is based upon the estimated income for the year, and adjustments, if any, in the applicable quarterly periods for the potential tax consequences, benefits, resolutions of tax audits or other tax contingencies.

Our effective tax rate for the three months ended March 31, 2019 is lower than the statutory tax rate primarily due to a decrease in the deferred tax liability related to indefinite lived assets. Other than the deferred tax liability relating to indefinite lived asset, the Company is maintaining a full valuation allowance against the remaining net DTA position.

Our effective tax rate for the three months ended March 31, 2018 is higher than the statutory tax rate primarily due to a tax provision for state income taxes and an increase in the deferred tax liability related to indefinite lived assets.

Our effective tax rate for the six months ended March 31, 2019 is lower than the statutory tax rate primarily due to an decrease in the deferred tax liability related to indefinite lived assets. Other than the deferred tax liability relating to indefinite lived asset, the Company is maintaining a full valuation allowance against the remaining net DTA position.

Our effective tax rate for the six months ended March 31, 2018 is lower than the statutory tax rate primarily due to a tax provision for state income taxes and an increase in the deferred tax liability related to indefinite lived assets being offset by a discrete tax benefit recorded for the impact from the US Tax Reform. The tax provision for the six months ended March 31, 2018 includes discrete tax benefit totaling $0.4 million relating to the US Tax Reform that was recorded in the period ending December 31, 2017.