Statements of Cash Flows (Unaudited) - USD ($)	6 Months Ended
	Sep. 30, 2020	Sep. 30, 2019
Net income	$ 4,634,205	$ 7,429,481
Adjustments to reconcile net income to net cash provided by operating activities:
Depreciation and amortization	259,241	266,916
Stock-based compensation	37,022	48,360
Deferred income taxes	(61,437)	75,521
Changes in operating assets and liabilities:
Accounts receivable	771,942	(220,147)
Inventories	(44,074)	(90,456)
Prepaid expenses and other assets	108,697	41,687
Accounts payable and other liabilities	(164,625)	(130,726)
Net cash provided by operating activities	5,540,971	7,420,636
INVESTING ACTIVITIES
Purchases of fixed assets		(16,100)
Purchases of marketable securities		(3,013,530)
Proceeds from maturities of marketable securities		12,500,000
Cash provided by investing activities		9,470,370
FINANCING ACTIVITIES
Repurchase of common stock	(91,419)
Payment of dividends to shareholders	(9,670,076)	(9,692,020)
Cash used in financing activities	(9,761,495)	(9,692,020)
(Decrease) increase in cash and cash equivalents	(4,220,524)	7,198,986
Cash and cash equivalents at beginning of period	8,065,594	6,877,304
Cash and cash equivalents at end of period	3,845,070	14,076,290
Supplemental disclosures of cash flow information:
Cash paid during the period for income taxes	$ 934,788	$ 1,230,000