Table:
year
total youth crime severity index
youth violent crime severity index
youth non-violent crime severity index

index
percent change from previous year
index
percent change from previous year
index
percent change from previous year

2007
101.5
1
102.1
2
101.0
1

2008
95.7
-6
95.7
-6
95.6
-5

2009
95.6
0
96.7
1
94.7
-1

2010
90.0
-6
93.2
-4
87.6
-8

2011
81.7
-9
87.4
-6
77.2
-12

2012
77.3
-5
82.2
-6
73.5
-5

2013
66.2
-14
71.3
-13
62.3
-15

2014
61.0
-8
65.3
-8
57.8
-7

2015
61.3
0
67.4
3
56.7
-2

2016r
61.2
0
72.5
8
52.9
-7

2017
63.3
3
81.2
12
50.6
-4

percent change 2007 to 2017
-38
..
-20
..
-50
..

Statement: in contrast, the youth non-violent csi decreased 4% in 2017.
Question: what was the percent change in the youth non-violent csi from previous year in 2017?
Answer: [-4.0]