Evaluation of the PLC's performance
		Frequency	Percent	Valid Percent	Cumulative Percent
Valid	Positive	317	37.7	41.5	41.5
	Neutral	162	19.3	21.2	62.8
	Negative	284	33.8	37.2	100.0
	Total	763	90.8	100.0
Missing	System	77	9.2
Total		840	100.0