Looking for help modeling ARIMA in R..... Here is the data:

Year Quarter UN GDP 1955 1 225 81.37

2 208 82.6

3 201 82.3

4 199 83 1956 1 207 82.87

2 215 83.6

3 240 83.33

4 245 83.53 1957 1 295 84.27

2 293 85.5

3 279 84.33

4 287 84.3 1958 1 331 85.07

2 396 83.6

3 432 84.37

4 462 84.5 1959 1 454 85.2

2 446 87.07

3 426 88.4

4 402 90.03 1960 1 363 92.3

2 342 92.13

3 325 93.17

4 312 93.5 1961 1 291 94.77

2 293 95.37

3 304 95.03

4 330 95.23 1962 1 357 95.07

2 401 96.4

3 447 96.97

4 483 96.5 1963 1 535 96.16

2 520 99.79

3 489 101.14

4 456 102.95 1964 1 386 103.96

2 368 105.28

3 358 105.81

4 330 107.14 1965 1 306 108.07

2 304 107.64

3 321 108.87

4 305 109.75 1966 1 279 110.2

2 282 110.2

3 318 110.9

4 414 110.4 1967 1 463 111

2 506 112.1

3 538 112.5

4 536 113 1968 1 544 114.3

2 541 115.1

3 547 116.4

4 532 117.8 1969 1 532 116.8

2 519 117.8

3 547 119

4 544 119.6