Statements of Cash Flows (Unaudited) - USD ($)	6 Months Ended
	Sep. 30, 2016		Sep. 30, 2015
OPERATING ACTIVITIES
Net income	$ 6,437,742		$ 7,114,021
Adjustments to reconcile net income to net cash provided by operating activities:
Depreciation	392,546		414,634
Stock-based compensation	22,000		21,160
Excess tax deficiencies (benefits)	1,369		(352,294)
Deferred income taxes	(64,915)		340,608
Changes in operating assets and liabilities:
Accounts receivable	(1,124,084)		181,006
Inventories	296,352		594,624
Prepaid expenses and other assets	36,736		(60,410)
Accounts payable and accrued expenses	(674)		(412,767)
Deferred revenue	(330,928)
Net cash provided by operating activities	5,666,144		7,840,582
INVESTING ACTIVITIES
Purchases of fixed assets	(153,096)		(146,505)
Purchases of marketable securities	(6,928,028)		266,240
Proceeds from maturities and sales of marketable securities	9,200,000		6,250,000
Net cash provided by investing activities	2,118,876		6,369,735
FINANCING ACTIVITIES
Proceeds from sale of common stock	42,449		292,909
Excess tax (deficiencies) benefits	(1,369)		352,294
Repurchase of common stock			(1,851,290)
Payment of dividends to shareholders	(9,670,020)		(9,725,174)
Net cash used in financing activities	(9,628,940)		(10,931,261)
(Decrease) increase in cash and cash equivalents	(1,843,920)		3,279,056
Cash and cash equivalents at beginning of period	7,534,593	[1]	9,437,262
Cash and cash equivalents at end of period	5,690,673		12,716,318
Supplemental disclosures of cash flow information:
Cash paid during the period for income taxes	$ 3,045,000		$ 3,240,000

[1] The March 31, 2016 Balance Sheet is derived from the audited financial statements contained in our Annual Report on Form 10-K for the fiscal year ended March 31, 2016.