ION GEOPHYSICAL CORP

CUSIP: 462044108 Class: COM

NEW YORK STATE TEACHERS RETIREMENT SYSTEM's Holding History (CIK: 0000314969)

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

Q3 2015
Shares 405,582 Value ($000) $158 Avg Close — Range —
Q2 2015
Shares 405,582 Value ($000) $434 Avg Close — Range —
Q1 2015
Shares 415,082 Value ($000) $901 Avg Close — Range —
Q4 2014
Shares 415,082 Value ($000) $1,141 Avg Close — Range —
Q3 2014
Shares 415,082 Value ($000) $1,158 Avg Close — Range —
Q2 2014
Shares 415,082 Value ($000) $1,752 Avg Close — Range —
Q1 2014
Shares 415,082 Value ($000) $1,747 Avg Close — Range —
Q4 2013
Shares 418,382 Value ($000) $1,381 Avg Close — Range —
Q3 2013
Shares 442,149 Value ($000) $2,299 Avg Close — Range —
Q2 2013
Shares 447,849 Value ($000) $2,696 Avg Close — Range —