marketing expenses in the current-year period compared to the prior-year period. As a percentage of net sales, SG&A increased by 240 basis points to 24.2% for the thirteen weeks ended September 24, 2022 from 21.8% for the thirteen weeks ended September 25, 2021. SG&A expenses as a percentage of net sales increased by 240 basis points primarily as a result of higher marketing expenses, other store-related expenses and higher store payroll.
Income from operations. Income from operations decreased $6.0 million, or 11.9%, to $44.2 million for the thirteen weeks ended September 24, 2022 from $50.1 million for the thirteen weeks ended September 25, 2021. The decrease in income from operations was attributable to the factors noted above. As a percentage of net sales, income from operations was 12.6% and 16.0% for the thirteen weeks ended September 24, 2022 and September 25, 2021, respectively.
Interest expense. Interest expense was $1.4 million and $1.2 million for the thirteen weeks ended September 24, 2022 and September 25, 2021, respectively. The increase in interest expense in the current-year period was primarily the result of a higher debt balance in the current year, partially offset by a lower weighted average interest rate compared to the prior-year period.
Income tax expense. Income tax expense was $10.7 million for the thirteen weeks ended September 24, 2022, compared to $11.1 million for the thirteen weeks ended September 25, 2021. Our effective tax rate was 25.1% and 22.7% for the thirteen weeks ended September 24, 2022 and September 25, 2021, respectively. The tax rate for the thirteen weeks ended September 24, 2022 was higher than the tax rate for the thirteen weeks ended September 25, 2021, primarily due to a lower tax benefit due to income tax accounting for share-based compensation compared to a higher tax benefit in the thirteen weeks ended September 25, 2021.
Net income. Net income was $32.1 million for the thirteen weeks ended September 24, 2022 compared to $37.9 million for the thirteen weeks ended September 25, 2021. The decrease in net income was primarily attributable to the factors noted above.
Twenty-Six Weeks Ended September 24, 2022 Compared to Twenty-Six Weeks Ended September 25, 2021
Net sales. Net sales increased $98.4 million, or 15.9%, to $717.4 million for the twenty-six weeks ended September 24, 2022 from $619.0 million for the twenty-six weeks ended September 25, 2021. Consolidated same store sales increased 6.1%. Excluding the impact of the 0.8% increase in e-commerce same store sales, same store sales increased by 7.0%. The increase in net sales was the result of the incremental sales from new stores opened over the past twelve months and an increase of 6.1% in consolidated same store sales, which saw an increase in average unit retail prices, driven in part by inflation.
Gross profit. Gross profit increased $32.3 million, or 13.8%, to $266.9 million for the twenty-six weeks ended September 24, 2022 from $234.6 million for the twenty-six weeks ended September 25, 2021. As a percentage of net sales, gross profit was 37.2% and 37.9% for the twenty-six weeks ended September 24, 2022 and September 25, 2021, respectively. Gross profit increased primarily due to higher sales. The decrease in gross profit rate of 70 basis points was driven by 110 basis points of deleverage in buying, occupancy and distribution center costs, partially offset by a 40 basis-point increase in merchandise margin rate. Merchandise margin rate increased 40 basis points despite a 30 basis-point headwind from increased freight charges. The increase in merchandise margin was driven primarily by growth in exclusive brand penetration and better full-price selling.
Selling, general and administrative expenses. SG&A expenses increased $39.5 million, or 30.2%, to $170.4 million for the twenty-six weeks ended September 24, 2022 from $130.8 million for the twenty-six weeks ended September 25, 2021. The increase in SG&A expenses was primarily a result of higher store payroll, other store-related expenses and marketing expenses in the current-year period compared to the prior-year period. As a percentage of net sales, SG&A increased by 260 basis points to 23.7% for the twenty-six weeks ended September 24, 2022 from 21.1% for the twenty-six weeks ended September 25, 2021. SG&A expenses as a percentage of net sales increased by 260 basis points primarily as a result of an increase in other store-related expenses, store payroll and marketing expenses.
Income from operations. Income from operations decreased $7.2 million, or 6.9%, to $96.6 million for the twenty-six weeks ended September 24, 2022 from $103.8 million for the twenty-six weeks ended September 25, 2021. The