NORTHWESTERN CORP

Ticker: NWE CUSIP: 668074305 Class: EQTY

Robeco Institutional Asset Management B.V.'s Holding History (CIK: 0001418773)

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

Q2 2020

Shares 21,244 Value ($000) $1,158 Avg Close $44.67 Range $39.68 - $50.33

Q1 2020

Shares 149,575 Value ($000) $8,950 Avg Close $54.52 Range $34.68 - $61.46

Q4 2019

Shares 189,485 Value ($000) $13,581 Avg Close $54.65 Range $51.50 - $57.67

Q3 2019

Shares 272,999 Value ($000) $20,491 Avg Close $54.27 Range $50.60 - $58.08

Q2 2019

Shares 299,905 Value ($000) $21,640 Avg Close $53.01 Range $50.21 - $55.53

Q1 2019

Shares 299,905 Value ($000) $21,117 Avg Close $48.59 Range $42.38 - $53.49

Q4 2018

Shares 299,905 Value ($000) $17,844 Avg Close $45.03 Range $41.21 - $48.18

Q3 2018

Shares 302,290 Value ($000) $17,734 Avg Close $43.15 Range $40.65 - $45.13

Q2 2018

Shares 302,290 Value ($000) $17,308 Avg Close $39.06 Range $37.03 - $41.93

Q1 2018

Shares 10,062 Value ($000) $541 Avg Close $37.69 Range $35.55 - $42.53

Q4 2017

Shares 10,062 Value ($000) $601 Avg Close $42.54 Range $39.78 - $45.45

Q3 2017

Shares 10,062 Value ($000) $573 Avg Close $41.74 Range $40.09 - $43.18

Q2 2017

Shares 10,062 Value ($000) $614 Avg Close $42.35 Range $40.29 - $44.62

Q1 2017

Shares 10,062 Value ($000) $591 Avg Close $39.52 Range $38.19 - $41.05

Q4 2016

Shares 10,062 Value ($000) $572 Avg Close $38.33 Range $36.64 - $40.23

Q3 2016

Shares 12,081 Value ($000) $695 Avg Close $40.31 Range $38.22 - $43.00

Q2 2016

Shares 12,081 Value ($000) $762 Avg Close $39.68 Range $37.02 - $42.70

Q1 2016

Shares 12,081 Value ($000) $746 Avg Close $38.33 Range $34.60 - $41.62

Q4 2015

Shares 12,081 Value ($000) $655 Avg Close $35.84 Range $33.71 - $37.52

Q3 2015

Shares 13,865 Value ($000) $746 Avg Close $34.01 Range $31.66 - $36.90

Q2 2015

Shares 13,865 Value ($000) $676 Avg Close $33.40 Range $31.54 - $35.25

Q1 2015

Shares 13,865 Value ($000) $746 Avg Close $35.30 Range $32.73 - $38.16

Q4 2014

Shares 13,865 Value ($000) $784 Avg Close $33.16 Range $28.63 - $37.51

Q3 2014

Shares 13,865 Value ($000) $629 Avg Close $30.29 Range $28.46 - $33.15

Q2 2014

Shares 13,865 Value ($000) $724 Avg Close $30.04 Range $28.38 - $33.02

Q1 2014

Shares 13,865 Value ($000) $658 Avg Close $27.98 Range $26.36 - $29.86

Q4 2013

Shares 13,865 Value ($000) $601 Avg Close $27.40 Range $25.54 - $28.91

Q3 2013

Shares 13,865 Value ($000) $623 Avg Close $25.46 Range $23.73 - $28.10

Period	Shares	Value ($000)	Average Close	Price Range
Q2 2020	21,244	$1,158	$44.67	$39.68 - $50.33
Q1 2020	149,575	$8,950	$54.52	$34.68 - $61.46
Q4 2019	189,485	$13,581	$54.65	$51.50 - $57.67
Q3 2019	272,999	$20,491	$54.27	$50.60 - $58.08
Q2 2019	299,905	$21,640	$53.01	$50.21 - $55.53
Q1 2019	299,905	$21,117	$48.59	$42.38 - $53.49
Q4 2018	299,905	$17,844	$45.03	$41.21 - $48.18
Q3 2018	302,290	$17,734	$43.15	$40.65 - $45.13
Q2 2018	302,290	$17,308	$39.06	$37.03 - $41.93
Q1 2018	10,062	$541	$37.69	$35.55 - $42.53
Q4 2017	10,062	$601	$42.54	$39.78 - $45.45
Q3 2017	10,062	$573	$41.74	$40.09 - $43.18
Q2 2017	10,062	$614	$42.35	$40.29 - $44.62
Q1 2017	10,062	$591	$39.52	$38.19 - $41.05
Q4 2016	10,062	$572	$38.33	$36.64 - $40.23
Q3 2016	12,081	$695	$40.31	$38.22 - $43.00
Q2 2016	12,081	$762	$39.68	$37.02 - $42.70
Q1 2016	12,081	$746	$38.33	$34.60 - $41.62
Q4 2015	12,081	$655	$35.84	$33.71 - $37.52
Q3 2015	13,865	$746	$34.01	$31.66 - $36.90
Q2 2015	13,865	$676	$33.40	$31.54 - $35.25
Q1 2015	13,865	$746	$35.30	$32.73 - $38.16
Q4 2014	13,865	$784	$33.16	$28.63 - $37.51
Q3 2014	13,865	$629	$30.29	$28.46 - $33.15
Q2 2014	13,865	$724	$30.04	$28.38 - $33.02
Q1 2014	13,865	$658	$27.98	$26.36 - $29.86
Q4 2013	13,865	$601	$27.40	$25.54 - $28.91
Q3 2013	13,865	$623	$25.46	$23.73 - $28.10