Note 5 - Fair Value of Financial Instruments - Investment Securities With Unrealized Losses (Details) - USD ($)	Sep. 30, 2022	Mar. 31, 2022
Fair market value, less than 12 months	$ 40,510,241	$ 6,306,750
Gross unrealized losses, less than 12 months	(1,327,302)	(23,727)
Fair market value, 12 months or greater	9,331,091	9,738,338
Gross unrealized losses, 12 months or greater	(956,409)	(613,578)
Total fair market value	49,841,332	16,045,088
Total gross unrealized losses	(2,283,711)	(637,305)
Corporate Bond Securities [Member]
Fair market value, less than 12 months	40,510,241	6,306,750
Gross unrealized losses, less than 12 months	(1,327,302)	(23,727)
Fair market value, 12 months or greater	9,331,091	9,738,338
Gross unrealized losses, 12 months or greater	(956,409)	(613,578)
Total fair market value	49,841,332	16,045,088
Total gross unrealized losses	$ (2,283,711)	$ (637,305)

Amount of investment in debt security measured at fair value with change in fair value recognized in other comprehensive income (available-for-sale), in continuous unrealized loss position for more than 12 months, without allowance for credit loss. Includes beneficial interest in securitized financial asset.

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