50-56: 7
57-63: 8
64-70: 9
71-77: 10
78-84: 11
85-91: 12
91-98: 13
99-105: 14
106-112: 15
113-119: 16
120-126: 17
127-133: 18
134-140: 19
141-147: 20
148-154: 21
the total deck count includes Lost Souls. So it's:
[43-49] + 7 = [50-56]
...
[127-133] + 21 = [148-154]