Time

Observed values

GM (1, 1) model

GM (1, 1) model with the second parameter fitting

GM (1, 1) with second parameter fitting-Markov model

Fitted values (m³/t)

Relative error %

Fitted value

(m³/t)

residual (m³/t)

Relative error %

Fitted value

(m³/t)

Residual

(m³/t)

Relative error

%

2005

10.60

10.60

0.00

10.60

0.00

0.00

10.60

0

0.00

2006

9.80

10.47

−6.79

10.16

−0.36

−3.72

9.66

0.14

1.43

2007

11.30

10.80

4.40

10.85

0.45

3.95

11.60

−0.3

−2.65

2008

10.40

11.15

−7.23

11.20

−0.80

−7.73

10.70

−0.3

−2.88

2009

12.50

11.51

7.91

11.57

0.93

7.48

12.32

0.18

1.44

2010

11.70

11.88

−1.56

11.94

−0.24

−2.04

11.44

0.26

2.22

2011

13.20

12.27

7.08

12.32

0.88

6.64

13.07

0.13

0.98

2012

11.30

12.66

−12.05

12.72

−1.42

−12.58

11.50

−0.2

−1.77

2013

13.80

13.07

5.29

13.13

0.67

4.84

13.38

0.42

3.04

2014

14.20

13.49

4.99

13.56

0.64

4.54

14.31

−0.11

−0.77

2015

12.90

13.93

−7.96

13.99

−1.09

−8.47

12.77

0.13

1.01

2016

14.50

14.38

0.85

14.44

0.06

0.39

14.69

−0.19

−1.31

2017

14.10

14.84

−5.25

14.91

−0.81

−5.74

14.41

−0.31

−2.2