Depreciation expense increased to $2,514,000 in the first nine months of 2021 from $2,289,000 in the first nine months of 2020, primarily from capital additions related to the reopening of the Nashville Superspeedway.
Gain on sale of land in 2021 and 2020 relates to the sale of approximately 350 and 97 acres of land at our Nashville facility, respectively.
Benefit for contingent obligation was $541,000 in the first nine months of 2021 compared to $112,000 in the first nine months of 2020. The 2021 benefit was primarily from higher than anticipated sales taxes collected to be allocated to the bond fund and used for debt service. The 2020 benefit was primarily from an increase in projected sales taxes to be collected as a result of our four-year sanction agreement with NASCAR for Nashville Superspeedway and from lower estimated interest rates on the bonds.
Other income of $357,000 in the first nine months of 2021 represents pension benefits and gains on equity securities. Other income of $115,000 in the first nine months of 2020 primarily represents pension benefits.
Our effective income tax rates for the first nine months of 2021 and 2020 were 25.9% and 13.3%, respectively. The 2020 rate was reduced by the reversal of a portion of the valuation allowance for Tennessee state income tax assets.
Liquidity and Capital Resources
Our operations and cash flows from operating activities are seasonal in nature.
Net cash provided by operating activities was $9,389,000 for the first nine months of 2021 compared to $8,440,000 for the first nine months of 2020. The higher net cash provided in 2021 was primarily from higher earnings from operations and the timing of tax payments, partially offset by the timing of payments related to the June 2021 NASCAR weekend.
Net cash provided by investing activities was $3,339,000 for the first nine months of 2021 compared to $5,404,000 for the first nine months of 2020. Capital expenditures of $10,489,000 in the first nine months of 2021 were primarily for facility improvements related to the reopening of Nashville Superspeedway. Capital expenditures of $545,000 in the first nine months of 2020 related primarily to equipment purchases, property improvements and expenditures related to the reopening of Nashville Superspeedway. In May 2021, we closed on the sale of approximately 350 acres of land at our Nashville Superspeedway facility for proceeds of $14,326,000, net of closing costs. The buyer had previously paid to us a $500,000 deposit that was credited to the purchase price. In July 2020, we closed on the sale of approximately 97 acres of land at our Nashville Superspeedway facility for $6,460,000, net of closing costs. The buyer had previously paid to us a $500,000 deposit that was credited to the purchase price.
Net cash used in financing activities was $1,613,000 for the first nine months of 2021 compared to $94,000 for the first nine months of 2020. We paid $1,458,000 in cash dividends in June of 2021. We purchased 51,791 and 50,572 shares of our outstanding common stock for $117,000 and $94,000 during the first nine months of 2021 and 2020, respectively, from employees in connection with the vesting of restricted stock awards under our stock incentive plan.
At September 30, 2021, Dover Motorsports, Inc. and its wholly owned subsidiaries Dover International Speedway, Inc. and Nashville Speedway, USA, Inc., as co-borrowers, had a $25,000,000 credit agreement with a bank group. On February 25, 2021, we modified the credit agreement: (1) to extend the maturity date to September 1, 2024; (2) to reduce the total available borrowings under the facility from $30,000,000 to $25,000,000; and (3) to replace the fixed charge coverage ratio with an interest coverage ratio. Interest is based upon LIBOR plus a margin that varies between 125 and 175 basis points depending on the leverage ratio. At September 30, 2021, there were no borrowings outstanding under the credit facility. The credit facility contains certain covenants including maximum funded debt to earnings before interest, taxes, depreciation and amortization (“leverage ratio”) and a minimum interest coverage ratio. Material adverse changes in our results of operations could impact our ability to maintain financial ratios necessary to satisfy these requirements. In addition, the credit agreement includes a material adverse change clause. The credit facility also provides that if we default under any other loan agreement that would be a default under this facility. At September 30, 2021, we were in compliance with the terms of the credit facility. The credit facility provides for seasonal funding needs, capital improvements, letter of credit requirements and other general corporate purposes. After consideration of stand-by letters of credit outstanding, the remaining maximum borrowings available pursuant to the credit facility were $13,612,000 at September 30, 2021. We expect to be in compliance with the financial covenants, and all other covenants, for all measurement periods during the next twelve months.
On August 17, 2017, we entered into an agreement with an entity owned by Panattoni Development Company (the “buyer”) relative to the sale of approximately 147 acres of land at our Nashville facility at a purchase price of $35,000 per acre. On March 2, 2018, we closed on the sale of the property with proceeds, less closing costs, of $4,945,000. Net proceeds after taxes were approximately $4,150,000 resulting in a gain of $2,512,000. On September 1, 2017, we also awarded to the buyer a three year option for approximately