DAWSON GEOPHYSICAL CO

CUSIP: 239359102 Class: CMN

DIMENSIONAL FUND ADVISORS LP's Holding History (CIK: 0000354204)

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

Q4 2014
Shares 624,623 Value ($000) $7,639 Avg Close — Range —
Q3 2014
Shares 628,626 Value ($000) $11,429 Avg Close — Range —
Q2 2014
Shares 632,420 Value ($000) $18,119 Avg Close — Range —
Q1 2014
Shares 632,216 Value ($000) $17,709 Avg Close — Range —
Q4 2013
Shares 634,853 Value ($000) $21,471 Avg Close — Range —
Q3 2013
Shares 631,755 Value ($000) $20,513 Avg Close — Range —
Q2 2013
Shares 610,909 Value ($000) $22,518 Avg Close — Range —