Year

Total Ningxia section

Boundary

~ Xiaheyan

Xiaheyan

~ Qingtongxia

Qingtongxia

~ Shizuishan

Shizuishan

~ Boundary

1999

36.868

6.021

7.579

21.881

1.387

2000

35.783

5.239

7.130

21.850

1.563

2001

32.173

4.702

8.259

17.102

2.110

2002

30.411

4.585

9.923

14.339

1.564

2003

21.613

2.406

5.103

12.030

2.075

2004

33.727

4.381

8.662

18.385

2.298

2005

35.416

4.121

9.013

20.151

2.132

2006

35.258

4.749

9.035

18.241

3.234

2007

31.354

4.521

5.947

19.570

1.316

2008

38.748

4.799

12.798

20.058

1.092

2009

36.195

4.637

11.678

18.324

1.556

2010

30.019

4.489

12.278

12.718

0.534

2011

31.727

5.636

11.734

13.815

0.541

2012

27.657

4.677

11.371

11.175

0.433

Average

32.639

4.640

9.322

17.117

1.560