Statements of Cash Flows (Unaudited) - USD ($)	6 Months Ended
	Sep. 30, 2021	Sep. 30, 2020
OPERATING ACTIVITIES
Net income	$ 7,226,073	$ 4,634,205
Adjustments to reconcile net income to net cash provided by operating activities:
Depreciation and amortization	271,207	259,241
Stock-based compensation	64,237	37,022
Deferred income taxes	16,539	(61,437)
Changes in operating assets and liabilities:
Accounts receivable	(911,821)	771,942
Inventories	(81,994)	(44,074)
Prepaid expenses and other assets	(298,099)	108,697
Accounts payable and other liabilities	172,054	(164,625)
Net cash provided by operating activities	6,458,196	5,540,971
INVESTING ACTIVITIES
Purchases of fixed assets	(73,916)	0
Proceeds from maturities of marketable securities	4,000,000	0
Cash used in investing activities	3,926,084	0
FINANCING ACTIVITIES
Repurchase of common stock		(91,419)
Payment of dividends to shareholders	(9,666,464)	(9,670,076)
Cash used in financing activities	(9,666,464)	(9,761,495)
Increase in cash and cash equivalents	717,816	(4,220,524)
Cash and cash equivalents at beginning of period	10,427,340	8,065,594
Cash and cash equivalents at end of period	11,145,156	3,845,070
Supplemental disclosures of cash flow information:
Cash paid during the period for income taxes	$ 1,760,000	$ 934,788