problems with structural sbknown

[Felipe Damasceno]

I'm using Stata 14 with Windowns 10 OS.

I want to test for structural breaks using sbknown. The problem is that I'm rejecting H0 for every date that I test, including those that should have no break. Something is going wrong and I can't figure out what. Here is my data. I'm also attaching a graph identifying which dates I feel I should test. The code I'm using is the following.

Can anyone please help me figure this out?

regress meanDI date2
estat sbknown, break(tm(date))

* Example generated by -dataex-. To install: ssc install dataex
clear
input float(meanDI date2)
 4.661818 420
    5.315 421
 5.632174 422
 7.302941 423
 5.707727 424
 5.676667 425
 5.620476 426
 4.876956 427
   4.8055 428
4.3042855 429
    4.201 430
    4.037 431
 3.449091 432
 3.603158 433
 3.107619 434
    3.022 435
 2.707727 436
 3.036316 437
2.4730434 438
 2.638636 439
 2.668095 440
     2.51 441
    2.669 442
2.5366666 443
 2.354091 444
 2.746111 445
2.5473685 446
 2.347619 447
     2.35 448
2.2571428 449
2.0786955 450
2.2414286 451
     2.14 452
 2.176087 453
    4.415 454
 3.920909 455
 37.13524 456
   33.905 457
28.035454 458
24.989473 459
   22.563 460
20.939524 461
 20.20739 462
 19.17476 463
34.635715 464
  41.3419 465
  37.8005 466
 30.90818 467
  31.1515 468
 38.41555 469
 42.51783 470
34.805264 471
26.269524 472
21.483334 473
 20.24636 474
 19.21727 475
19.107143 476
   18.768 477
   18.739 478
18.771305 479
18.734285 480
 18.72381 481
18.700476 482
 18.43421 483
 18.43591 484
    17.95 485
 16.78619 486
16.391304 487
   16.465 488
16.481905 489
   16.444 490
  16.1285 491
 15.40409 492
     15.1 493
 15.29182 494
  15.9345 495
16.397272 496
  17.2825 497
   18.615 498
19.011305 499
19.042631 500
19.050909 501
  19.0465 502
   19.051 503
19.022272 504
18.953888 505
  18.7015 506
18.366817 507
18.207144 508
  17.8215 509
 18.14913 510
17.868181 511
17.887142 512
 19.53739 513
  21.1385 514
 22.92143 515
 24.97591 516
  25.6325 517
26.252106 518
   26.231 519
end
format %tm date2