DAWSON GEOPHYSICAL CO

CUSIP: 239359102 Class: CMN

CALIFORNIA STATE TEACHERS RETIREMENT SYSTEM's Holding History (CIK: 0001081019)

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

Q4 2014
Shares 14,828 Value ($000) $181 Avg Close — Range —
Q3 2014
Shares 14,764 Value ($000) $268 Avg Close — Range —
Q2 2014
Shares 14,679 Value ($000) $421 Avg Close — Range —
Q1 2014
Shares 14,579 Value ($000) $408 Avg Close — Range —
Q4 2013
Shares 14,579 Value ($000) $493 Avg Close — Range —
Q3 2013
Shares 14,479 Value ($000) $470 Avg Close — Range —
Q2 2013
Shares 14,033 Value ($000) $517 Avg Close — Range —
Q1 2013
Shares 13,788 Value ($000) $414 Avg Close — Range —