Start means (Example) 

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158146  158367  i  11,peter,JJ113952
135588  136297  8  12,peter,JJ113952
135356  135449  3  13,peter,JJ113952

In this start means this record which comes first
158146  158367  i  11,peter,JJ113952

and End means this record which comes last
135356  135449  3  13,peter,JJ113952
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Unique means this record 
62556   63635   y   1,andrew,JJ113954