STOCK PLANS AND STOCK-BASED COMPENSATION - Stock option activity (Details) - $ / shares	3 Months Ended
Jun. 30, 2021	Jun. 30, 2020
Number of Shares
Balance, beginning of year	23,332	43,332
Options exercised	0	(5,000)
Balance, end of year	23,332	38,332
Weighted Average Exercise Price
Balance, beginning of year	$ 2.78	$ 2.69
Options exercised		1.97
Balance, end of year	$ 2.78	$ 2.78

Number of options outstanding, including both vested and non-vested options.

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A roll forward is a reconciliation of a concept from the beginning of a period to the end of a period.

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Weighted average price at which grantees can acquire the shares reserved for issuance under the stock option plan.

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- Definition

Weighted average price at which option holders acquired shares when converting their stock options into shares.

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Number of share options (or share units) exercised during the current period.

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