Balance Sheets - USD ($)	Mar. 31, 2019	Mar. 31, 2018
ASSETS
Cash and cash equivalents	$ 6,877,304	$ 4,755,082
Marketable securities, short-term	12,487,821	20,765,809
Accounts receivable, net of allowance for uncollectible accounts of $15,000	2,995,638	2,888,779
Inventories	4,264,876	3,650,439
Prepaid expenses and other assets	816,045	635,160
Total current assets	27,441,684	32,695,269
Fixed assets
Machinery and equipment	9,365,806	9,395,987
Leasehold improvements	1,787,269	1,749,284
	11,153,075	11,145,271
Less accumulated depreciation and amortization	10,258,240	9,819,888
Net fixed assets	894,835	1,325,383
Deferred tax assets	353,735	572,655
Marketable securities, long-term	54,925,633	52,838,158
Total assets	83,615,887	87,431,465
LIABILITIES AND SHAREHOLDERS’ EQUITY
Accounts payable	375,188	414,970
Accrued payroll and other	460,488	574,755
Total current liabilities	835,676	989,725
Shareholders’ equity
Common stock, $0.01 par value, 6,000,000 shares authorized; 4,846,010 issued and outstanding as of March 31, 2019 and 4,842,010 as of March 31, 2018	48,460	48,420
Additional paid-in capital	19,910,558	19,599,298
Accumulated other comprehensive loss	(82,725)	(915,635)
Retained earnings	62,903,918	67,709,657
Total shareholders’ equity	82,780,211	86,441,740
Total liabilities and shareholders’ equity	$ 83,615,887	$ 87,431,465