Here is my tracking data. I’ve only been tracking Arcanes:
First 10 arcanes before tracking but I switched to assassin class before doing exploring at 0 battles in assassin class and 0 of the needed arcane
Arcane 11 - 198
Arcane 12 - 230
Arcane 13 - 244
Arcane 14 - 253
14/253 set
14/253 total
(changed to archer class, 2913 start)
Arcane 15 - 2950
Arcane 16 - 2974
Arcane 17 - 2977
Arcane 18 - 2989
Arcane 19 - 2992
Arcane 20 - 2993
6/80 set
20/333 total
(pvp 2994 - 3120)
Arcane 21 - 3129
Arcane 22 - 3131
Arcane 23 - 3132
Arcane 24 - 3140
Arcane 25 - 3157
Arcane 26 - 3178
Arcane 27 - 3208
Arcane 28 - 3219
Arcane 29 - 3222
Arcane 30 - 3242
Arcane 31 - 3277
Arcane 32 - 3288
Arcane 33 - 3307
Arcane 34 - 3313
Arcane 35 - 3321
Arcane 36 - 3338
Arcane 37 - 3362
Arcane 38 - 3365
Arcane 39 - 3391
Arcane 40 - 3405
Arcane 41 - 3407
Arcane 42 - 3411
Arcane 43 - 3476
23/356 set
43/689 so far
(3477-3506 pvp - 1 arcane dropped here, not counted in totals)
Arcane 44 - 3516
Arcane 45 - 3517
Arcane 46 - 3531
Arcane 47 - 3541
Arcane 48 - 3565
Arcane 49 - 3570
Arcane 50 - 3580
7/74 set
50/763 so far
(3581-3621 pvp)
Arcane 51 - 3637
Arcane 52 - 3642
Arcane 53 - 3649
Arcane 54 - 3656
Arcane 55 - 3666
Arcane 56 - 3682
Arcane 57 - 3685
Arcane 58 - 3727
Arcane 59 - 3755
Arcane 60 - 3774
Arcane 61 - 3796
Arcane 62 - 3803
12/193 set (counting the 11 battles after arcane 62 and before before PvP where I got none)
62/956 total so far
(3815-3863 pvp)
Arcane 63 - 3883
Arcane 64 - 3896
Arcane 65 - 3930
Arcane 66 - 3937
Arcane 67 - 3949
Arcane 68 - 3986
Arcane 69 - 4018
7/155 set
69/1111 total
(pvp 4019- xx)
Thats about 6.2% over the total right now, or about 1 in 16.1. Projected based on community estimated drops from challenges and past experience (1 in 50, not 1 in 30) and multiplied by 3 would have been a 6% drop rate, and I figure the actual is pretty close to that, as my sets contain more streaks than droughts.