Statements of Cash Flows (Unaudited) - USD ($)	9 Months Ended
	Dec. 31, 2015		Dec. 31, 2014
OPERATING ACTIVITIES
Net income	$ 9,691,472		$ 10,705,638
Adjustments to reconcile net income to net cash provided by operating activities:
Depreciation and amortization	628,186		698,820
Stock-based compensation	21,160		58,960
Excess tax benefits	(352,294)		(24,288)
Deferred income taxes	305,391		141,060
Changes in operating assets and liabilities:
Accounts receivable	1,210,285		476,495
Inventories	633,581		(478,791)
Prepaid expenses and other assets	(328,655)		(709,502)
Accounts payable and accrued expenses	(625,422)		$ (20,142)
Deferred revenue	714,805
Net cash provided by operating activities	11,898,509		$ 10,848,250
INVESTING ACTIVITIES
Purchases of fixed assets	(177,449)		(114,139)
Purchases of marketable securities	(9,613,052)		(9,136,457)
Proceeds from maturities and sales of marketable securities	7,825,000		8,610,000
Net cash used in investing activities	(1,965,501)		(640,596)
FINANCING ACTIVITIES
Proceeds from sale of common stock	292,909		302,701
Excess tax benefits	352,294		$ 24,288
Repurchase of common stock	(1,851,290)
Payment of dividends to shareholders	(14,570,019)
Net cash (used in) provided by financing activities	(15,776,106)		$ 326,989
(Decrease) increase in cash and cash equivalents	(5,843,098)		10,534,643
Cash and cash equivalents at beginning of period	9,437,262	[1]	1,262,300
Cash and cash equivalents at end of period	3,594,164		11,796,943
Supplemental disclosures of cash flow information:
Cash paid during the period for income taxes	$ 4,490,000		$ 5,600,000

[1] The March 31, 2015 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, 2015.