NORTHWEST NAT GAS CO

CUSIP: 667655104 Class: COM

COMMONWEALTH OF PENNSYLVANIA PUBLIC SCHOOL EMPLS RETRMT SYS's Holding History (CIK: 0001083190)

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

Q3 2018
Shares 6,021 Value ($000) $403 Avg Close — Range —
Q2 2018
Shares 6,089 Value ($000) $388 Avg Close — Range —