Balance Sheets - USD ($)	Mar. 31, 2022	Mar. 31, 2021
Current assets
Cash and cash equivalents	$ 10,449,510	$ 10,427,340
Marketable securities, short-term	20,839,683	7,678,957
Accounts receivable, net of allowance for uncollectible accounts of $15,000	4,704,829	1,964,281
Inventories	5,088,635	3,900,777
Prepaid expenses and other assets	420,520	391,278
Total current assets	41,503,177	24,362,633
Fixed assets
Machinery and equipment	9,739,244	9,254,664
Leasehold improvements	1,810,872	1,810,872
Property, Plant and Equipment, Gross, Ending Balance	11,550,116	11,065,536
Less accumulated depreciation and amortization	10,943,731	10,728,853
Net fixed assets	606,385	336,683
Deferred tax assets	483,469	73,538
Marketable securities, long-term	24,314,211	47,038,669
Right-of-use asset – operating lease	560,250	689,216
Total assets	67,467,492	72,500,739
Current liabilities
Accounts payable	943,535	336,591
Accrued payroll and other	1,356,689	540,474
Operating lease	156,121	150,273
Total current liabilities	2,456,345	1,027,338
Operating lease	446,018	581,459
Total liabilities	2,902,363	1,608,797
Shareholders’ equity
Common stock, $0.01 par value, 6,000,000 shares authorized; 4,830,826 issued and outstanding as of March 31, 2022 and 4,833,232 as of March 31, 2021	48,308	48,332
Additional paid-in capital	19,256,485	19,338,127
Accumulated other comprehensive income (loss)	(318,120)	1,101,119
Retained earnings	45,578,456	50,404,364
Total shareholders’ equity	64,565,129	70,891,942
Total liabilities and shareholders’ equity	$ 67,467,492	$ 72,500,739