Condensed Consolidated Balance Sheets - USD ($)	Aug. 31, 2021	May 31, 2021
Current assets:
Cash and cash equivalents	$ 20,146,836	$ 20,581,604
Short-term investments	1,101,705	1,097,012
Accounts and other receivables, net	2,756,295	4,120,564
Inventory	5,467,733	5,835,596
Costs and estimated earnings in excess of billings	3,287,460	1,499,604
Other current assets	913,361	977,525
Total current assets	33,673,390	34,111,905
Maintenance and other inventory, net	1,592,847	1,612,839
Property and equipment, net	9,964,762	9,816,594
Other assets	201,693	200,538
Deferred income taxes	190,115	190,115
Total assets	45,622,807	45,931,991
Current liabilities:
Accounts payable	1,945,783	1,787,325
Accrued commissions	460,169	269,064
Other current liabilities	1,265,512	1,715,409
Billings in excess of costs and estimated earnings	967,425	1,361,985
Total current liabilities	4,638,889	5,133,783
Stockholders' Equity:
Common stock and additional paid-in capital	10,115,568	10,111,735
Retained earnings	33,783,352	33,601,475
Stockholders’ equity before treasury stock	43,898,920	43,713,210
Treasury stock - at cost	(2,915,002)	(2,915,002)
Total stockholders’ equity	40,983,918	40,798,208
Total liabilities and stockholders’ equity	$ 45,622,807	$ 45,931,991