Consolidated Statements of Cash Flows (Unaudited) - USD ($)	9 Months Ended
	Feb. 28, 2018	Feb. 28, 2017
Cash Flows from Operating Activities:
Net income	$ 679,899	$ 1,133,317
Adjustments to reconcile net income to net cash provided by operating activities -
Depreciation and amortization	2,578,842	1,997,334
Deferred tax expense	882,100	556,700
Loss on sale of equipment	7,932
Decrease in trade accounts receivable	2,486,180	3,142,917
Decrease in related party receivables	18,498	28,536
Increase in inventory	(2,501,222)	(2,246,947)
Decrease (increase) in prepaid expenses	30,470	(87,243)
Increase (decrease) in accounts payable and accrued expenses	(2,778,406)	307,005
Increase in deferred revenue	4,595,034
Net cash provided by operating activities	5,999,327	4,831,619
Cash Flows from Investing Activities:
Purchase of property and equipment	(3,768,337)	(2,242,366)
Proceeds from sale of equipment	3,000
Net cash used in investing activities	(3,765,337)	(2,242,366)
Cash Flows from Financing Activities:
Proceeds from long-term debt	2,320,200
Payments on long-term debt and capitalized leases	(4,544,487)	(2,704,325)
Proceeds from revolving loan	240,000	500,000
Payments on revolving loan		(275,000)
Debt issue costs		(130,000)
Proceeds from exercised stock options		57,000
Dividends paid on preferred stock	(313,288)	(288,669)
Distributions paid by variable interest entity	(181,400)	(162,609)
Net cash used in financing activities	(2,478,975)	(3,003,603)
Net Decrease in Cash	(244,985)	(414,350)
Cash, beginning of period	579,021	897,377
Cash, end of period	334,036	483,027
Non-cash Activities:
Acquisition of equipment by capital lease	1,998,500	5,450,474
Equipment acquired from related party pursuant to long-term debt		1,469,713
Acquisition of building pursuant to long-term debt		318,750
Revolver loan converted to term loan	2,500,000
Conversion of related party accrued interest to long-term debt		2,475,690
Warrants to purchase common stock issued		120,000
Preferred dividend accrual		26,850
Supplemental information:
Interest paid	993,394	832,887
Income taxes paid	$ 10,000