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Note: These data are available in spreadsheet format by clicking the ''Download Series History'' link on the previous page (with drop-down menu bar at top).
View History:
Monthly
Annual
Midwest (PADD 2) Isobutane-Isobutylene Stock Change (Thousand Barrels)
Year
Jan
Feb
Mar
Apr
May
Jun
Jul
Aug
Sep
Oct
Nov
Dec
1981
221
-91
-215
133
-181
20
11
-267
144
-447
-91
50
1982
347
101
131
-107
-397
-180
-101
215
-55
485
158
-94
1983
159
-365
-37
249
104
123
424
-296
195
-298
-252
-305
1984
-49
185
11
-41
-69
-54
-224
-59
145
-24
-21
46
1985
74
-116
-508
70
47
-128
-109
-34
-78
134
346
99
1986
-34
-115
-177
365
-111
102
-84
-92
211
38
287
-286
1987
-201
-159
-35
-255
158
156
219
5
185
195
171
158
1988
-238
-264
-65
386
-292
-98
409
-77
98
-46
61
-241
1989
-135
-271
47
-70
293
151
108
208
36
-22
221
-433
1990
-20
-294
5
117
466
161
116
-170
366
-542
138
-267
1991
-112
-77
363
-389
-163
137
110
-28
289
48
-81
-64
1992
-46
158
56
116
-130
-33
-120
-193
426
171
-12
-110
1993
-299
57
302
371
-156
-33
186
109
221
-387
-519
-171
1994
107
220
295
-327
-380
-144
479
675
-17
-690
-783
-4
1995
-140
25
264
89
87
225
-83
544
236
-119
-847
-19
1996
-395
-145
49
126
281
-41
303
195
-156
-205
-34
-142
1997
-221
-271
-82
383
416
219
-76
-21
85
-352
-72
-20
1998
-307
471
-30
91
-170
181
-28
506
164
-795
-248
-92
1999
-58
-151
-140
57
235
69
174
12
-112
-85
80
-202
2000
-25
-157
165
69
-52
66
171
262
-67
-128
-145
5
2001
-238
-184
65
161
72
84
226
18
2
-288
-239
-20
2002
83
45
-120
107
293
-6
-5
259
-1
-186
-209
-87
2003
247
-115
44
-249
-115
388
135
25
128
-36
-3
-402
2004
-100
-91
485
-7
-23
68
102
145
430
-976
74
-13
2005
-110
63
169
-118
92
47
145
105
-220
-64
-174
151
2006
-81
-17
121
219
14
152
100
126
28
25
-43
-195
2007
-288
135
141
47
215
228
265
-75
151
-88
-387
-363
2008
-171
-266
172
2
Updated on 6/26/2008
Source: U.S. Energy Information Administration
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