Our corporate, all other membership increased by approximately 3,900 members in 2016 as a result of increased membership in our vision plan.
Self-Insured ASO Fees - Self-insured ASO fees decreased approximately $26,000, or 1.8%. Approximately $32,000 of this decrease is due to a decrease in average self-insured ASO fee rates for 2016 compared to 2015 and is slightly offset by an increase in membership for existing employer groups during 2016.
Self-insured dental revenue increased by approximately $1,956,000 due to new self-insured sales and an increase in membership for existing employer groups. Self-insured revenue increased by approximately $587,000 due to an increase in the self-insured claims revenue on a per member per month basis. Self-insured ASO fees increased due to those membership increases, offset by a slight decrease in self-insured administrative fee rates on a per member per month basis. The self-insured dental segment represented approximately 29.5% of our total dental business in 2015. The self-insured segment revenue has two components:
Cash decreased $436,000, or 3.7%, for the year ended December 31, 2016 to approximately $11,221,000 at December 31, 2016 from approximately $11,657,000 at December 31, 2015. This cash decrease is primarily the result of cash flow used in investing activities and financing activities of approximately $2,209,000 and $1,909,000, respectively. These were offset by an increase in cash flow provided from operations of approximately $3,682,000.
A mortgage note, secured by the land and the office building, accrues interest based on the 30-day LIBOR rate plus 1.95%. The note requires us to make principal payments of $4,400 per month in 2017 and higher principal payments in subsequent years through 2022 in accordance with the agreed upon loan amortization schedule. At the maturity date of the mortgage note in 2022, the expected outstanding balance of the note of approximately $804,000 must be repaid or refinanced. We also entered into an interest rate swap agreement that effectively changed the interest rate related to the $1,340,000 mortgage note with a commercial bank from a variable rate based on the 30-day LIBOR rate plus 1.95% to a fixed rate of approximately 3.90% for the 10-year period through December 2022. At December 31, 2016, the carrying value of the mortgage note approximates fair value. Under this mortgage, the Company is required to have a minimum tangible net worth equal to or greater than $3,500,000 at the end of each fiscal year and a debt service ratio of at least 1:1. The Company was in compliance with these covenants at December 31, 2016. The Company also entered into a capital lease agreement with a leasing company in 2015 that obligates the Company to pay lease payments over a four year period for each capital lease. Under these capital lease agreements, the Company is required to have a minimum tangible net worth equal to or greater than $2,500,000 at the end of each fiscal year. At December 31, 2016, the Company was in compliance with this minimum tangible net worth requirement.
In 2012, the Company entered into a Preferred Shares Purchase Agreement (the “2012 Stock Purchase Agreement”) with an investor. Pursuant to the 2012 Stock Purchase Agreement, the investor agreed to purchase 1,000 shares of Redeemable Institutional Preferred Shares at a purchase price of $1,000 per share, for an aggregate purchase price of $1,000,000. The annual dividend payable on each share is 5% of the book value at the beginning of the dividend period.
During 2016, 2015, and 2014, four fully-insured customers accounted for approximately 10%, 10%, and 9%, respectively, of the Company’s total premium revenue. Additionally, two self-insured customers accounted for approximately 11%, 11%, and 10% of the Company’s total revenue during each of the years 2016, 2015, and 2014, respectively.
In accordance with the 2006 Dental Care Plus Management Equity Incentive Plan and the Dental Care Plus, Inc. and DCP Holding Company Deferred Compensation Plan (the “Plans”), Company directors and certain key employees elected to defer portions of their director fees and employee compensation, as applicable. The Company recorded expense of approximately $61,000, $141,000, and $130,000 related to deferred director fees and deferred employee compensation for the years ended December 31, 2016, 2015 and 2014, respectively. Directors and key employees who elect to defer cash compensation may request that the Company invest this compensation in a mutual fund investment or phantom shares of the Company. The deferred cash compensation is included in the deferred compensation liability at December 31, 2016 and 2015.
The following is a summary of activity of non-vested awards for the years ended December 31, 2016 and 2015:
Dividend restrictions vary among the subsidiaries. Dental Care Plus is restricted by regulatory requirements of its domiciliary state, which limit by reference to statutory net income and net worth, the dividends that can be paid without prior regulatory approval. Dividends paid by Dental Care Plus cannot, without prior approval of the Ohio Department of Insurance, exceed in any one year the lesser of: (i) 10% of net worth (as of the preceding December 31), or (ii) net income for the prior year, and only if net worth exceeds $250,000 and only out of unassigned surplus. There were no dividends declared or paid by Dental Care Plus in 2016, 2015 or 2014. During 2017, the total dividend that the Dental Care Plus subsidiary may declare without prior regulatory approval is approximately $1,227,000.