NORTHWEST NAT GAS CO

CUSIP: 667655104 Class: COM

American Investment Services, Inc.'s Holding History (CIK: 0001369913)

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

Q3 2018
Shares 19,830 Value ($000) $1,327 Avg Close — Range —
Q2 2018
Shares 19,830 Value ($000) $1,265 Avg Close — Range —
Q1 2018
Shares 19,830 Value ($000) $1,143 Avg Close — Range —
Q4 2017
Shares 19,830 Value ($000) $1,183 Avg Close — Range —
Q3 2017
Shares 19,830 Value ($000) $1,277 Avg Close — Range —
Q2 2017
Shares 19,830 Value ($000) $1,187 Avg Close — Range —
Q1 2017
Shares 19,536 Value ($000) $1,155 Avg Close — Range —
Q4 2016
Shares 19,536 Value ($000) $1,168 Avg Close — Range —
Q3 2016
Shares 19,536 Value ($000) $1,174 Avg Close — Range —
Q2 2016
Shares 19,536 Value ($000) $1,266 Avg Close — Range —
Q1 2016
Shares 21,618 Value ($000) $1,164 Avg Close — Range —
Q4 2015
Shares 21,618 Value ($000) $1,094 Avg Close — Range —
Q3 2015
Shares 22,026 Value ($000) $1,010 Avg Close — Range —
Q2 2015
Shares 22,026 Value ($000) $929 Avg Close — Range —
Q1 2015
Shares 22,026 Value ($000) $1,056 Avg Close — Range —
Q4 2014
Shares 22,026 Value ($000) $1,099 Avg Close — Range —
Q3 2014
Shares 23,133 Value ($000) $977 Avg Close — Range —
Q2 2014
Shares 23,133 Value ($000) $1,091 Avg Close — Range —
Q1 2014
Shares 8,131 Value ($000) $358 Avg Close — Range —
Q4 2013
Shares 8,131 Value ($000) $348 Avg Close — Range —
Q3 2013
Shares 8,131 Value ($000) $341 Avg Close — Range —