NATURAL GAS SERVICES GROUP

Ticker: NGS CUSIP: 63886Q109 Class: Common Stock

AMICA MUTUAL INSURANCE CO's Holding History (CIK: 0000857508)

Note: Option positions (PUT/CALL) are excluded.

Q2 2013

Shares 157,486 Value ($000) $3,699 Avg Close $21.33 Range $18.17 - $23.75

Period	Shares	Value ($000)	Average Close	Price Range
Q2 2013	157,486	$3,699	$21.33	$18.17 - $23.75