Consolidated Statements of Cash Flows (Unaudited) - USD ($)	6 Months Ended
	Nov. 30, 2017	Nov. 30, 2016
Cash Flows from Operating Activities:
Net income	$ 674,353	$ 212,434
Adjustments to reconcile net income to net cash provided by operating activities -
Depreciation and amortization	1,612,143	1,222,574
Decrease in deferred tax asset	242,500	54,550
Decrease in trade accounts receivable	4,219,978	2,486,129
(Increase) Decrease in related party receivables	551	(22,142)
(Increase) Decrease in inventory	(1,452,384)	8,953
(Increase) Decrease in prepaid expenses	23,237	(157,932)
Increase (Decrease) in accounts payable and accrued expenses	(1,733,329)	239,547
Net cash provided by operating activities	3,587,049	4,044,113
Cash Flows from Investing Activities:
Purchase of property and equipment	(2,996,530)	(2,095,073)
Cash Flows from Financing Activities:
Proceeds from long-term debt	1,795,000
Payments on long-term debt and capitalized lease	(2,387,172)	(1,619,936)
Proceeds from revolving loan	240,000
Payments on revolving loan		(275,000)
Debt issue costs		(64,000)
Proceeds from exercised stock options		57,000
Dividends paid on preferred stock	(186,918)	(172,813)
Distributions paid by variable interest entity	(102,000)	(102,000)
Net cash used in financing activities	(641,090)	(2,176,749)
Net Decrease in Cash	(50,571)	(227,709)
Cash, beginning of period	579,021	897,377
Cash, end of period	528,450	669,668
Non-cash Activities:
Acquisition of equipment by capital lease		5,450,474
Conversion of related party accrued interest to long-term debt		2,475,690
Warrants to purchase common stock issued		120,000
Preferred dividend accrual	30,822	56,404
Supplemental information:
Interest paid	658,736	527,800
Taxes paid	$ 10,000