Statements of Cash Flows (Unaudited) - USD ($)	3 Months Ended
	Jun. 30, 2018		Jun. 30, 2017
OPERATING ACTIVITIES
Net income	$ 3,945,049		$ 3,297,615
Adjustments to reconcile net income to net cash provided by operating activities:
Depreciation and amortization	179,746		242,160
Deferred income taxes	(443)		(84,210)
Changes in operating assets and liabilities:
Accounts receivable	(231,994)		305,836
Inventories	28,758		109,553
Prepaid expenses and other assets	103,053		9,334
Accounts payable and accrued expenses	625,730		1,449,379
Deferred revenue			(107,100)
Net cash provided by operating activities	4,649,899		5,222,567
INVESTING ACTIVITIES
Purchases of fixed assets	(37,985)		(393,398)
Purchases of marketable securities	(3,373,125)		(3,809,610)
Proceeds from maturities of marketable securities	7,300,000
Cash provided by (used in) investing activities	3,888,890		(4,203,008)
FINANCING ACTIVITIES
Payment of dividends to shareholders	(4,842,010)		(4,841,010)
Cash used in financing activities	(4,842,010)		(4,841,010)
Increase (decrease) in cash and cash equivalents	3,696,779		(3,821,451)
Cash and cash equivalents at beginning of period	4,755,082	[1]	8,199,364
Cash and cash equivalents at end of period	8,451,861		4,377,913
Supplemental disclosures of cash flow information:
Cash paid during the period for income taxes	$ 11,222

[1] The March 31, 2018 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, 2018.