data.frame(comb)

##

DATE

GDP

GDP_per_capita

interest_rate

tax_to_gdp

##

1

1972-01-01

1279.112

25659.00

4.43416667

11.819937

##

2

1973-01-01

1425.376

26851.25

8.72750000

11.495212

##

3

1974-01-01

1545.243

26462.50

10.50250000

11.837620

##

4

1975-01-01

1684.905

26151.75

5.82416667

11.185800

##

5

1976-01-01

1873.412

27295.50

5.04500000

10.748837

##

6

1977-01-01

2081.825

28271.25

5.53750000

11.618646

##

7

1978-01-01

2351.599

29522.00

7.93083333

11.542359

##

8

1979-01-01

2627.326

30123.00

11.19416667

12.003808

##

9

1980-01-01

2857.309

29701.00

13.35583333

12.138353

##

10

1981-01-01

3207.041

30151.75

16.37833333

12.550510

##

11

1982-01-01

3343.789

29326.75

12.25833333

11.978627

##

12

1983-01-01

3634.037

30392.50

9.08666667

10.348268

##

13

1984-01-01

4037.614

32308.50

10.22500000

10.159716

##

14

1985-01-01

4338.980

33357.25

8.10083333

10.384240

##

15

1986-01-01

4579.632

34200.75

6.80500000

10.163046

##

16

1987-01-01

4855.216

35068.75

6.65750000

10.948846

##

17

1988-01-01

5236.438

36203.00

7.56833333

10.595943

##

18

1989-01-01

5641.579

37180.50

9.21666667

10.782440

##

19

1990-01-01

5963.145

37459.50

8.09916667

10.465285

##

20

1991-01-01

6158.129

36923.75

5.68750000

10.320342

##

21

1992-01-01

6520.327

37719.00

3.52166667

9.984162

##

22

1993-01-01

6858.559

38256.75

3.02250000

10.304934

##

23

1994-01-01

7287.236

39318.50

4.20166667

10.623507

##

24

1995-01-01

7639.749

39900.00

5.83666667

10.980989

##

25

1996-01-01

8073.122

40924.25

5.29833333

11.373915

##

26

1997-01-01

8577.552

42236.25

5.46000000

11.828197

##

27

1998-01-01

9062.817

43618.25

5.35333333

12.329829

##

28

1999-01-01

9631.172

45190.25

4.97000000

12.259979

##

29

2000-01-01

10250.952

46522.00

6.23583333

12.970800

##

30

2001-01-01

10581.929

46501.75

3.88750000

11.857704

##

31

2002-01-01

10929.108

46842.00

1.66666667

9.868012

##

32

2003-01-01

11456.450

47707.75

1.12750000

9.390699

##

33

2004-01-01

12217.196

49101.00

1.34916667

9.537473

##

34

2005-01-01

13039.197

50342.75

3.21333333

10.681731

##

35

2006-01-01

13815.583

51255.00

4.96416667

11.310476

##

36

2007-01-01

14474.227

51786.25

5.01916667

11.289914

##

37

2008-01-01

14769.862

51366.75

1.92750000

10.276191

##

38

2009-01-01

14478.067

49590.25

0.16000000

7.903518

##

39

2010-01-01

15048.970

50506.25

0.17500000

8.563226

##

40

2011-01-01

15599.732

50886.00

0.10166667

9.538931

##

41

2012-01-01

16253.970

51644.75

0.14000000

9.763916

##

42

2013-01-01

16843.196

52202.00

0.10750000

10.483509

##

43

2014-01-01

17550.688

52977.50

0.08916667

10.933181

##

44

2015-01-01

18206.023

53988.25

0.13250000

11.229008

##

45

2016-01-01

18695.106

54466.00

0.39500000

10.914137

##

46

2017-01-01

19477.337

55303.25

1.00166667

11.750297

##

47

2018-01-01

20533.057

56597.25

1.83166667

9.922180

##

48

2019-01-01

21380.976

57595.00

2.15833333

10.026620

##

49

2020-01-01

21060.474

55786.00

0.37583333

9.861612