Registration letter	Start date	Finish Date
------A	1 Feb 63	31 Dec 63
------B	1 Jan 64	31 Dec 64
------C	1 Jan 65	31 Dec 65
------D	1 Jan 66	31 Dec 66
------E	1 Jan67	31 Jul 67
------F	1 Aug 67	31 Jul 68
------G	1 Aug 68	31 Jul 69
------H	1 Aug 69	31 Jul 70
------J	1 Aug 70	31 Jul 71
------K	1 Aug 71	31 Jul 72
------L	1 Aug 72	31 Jul 73
------M	1 Aug 73	31 Jul 74
------N	1 Aug 74	31 Jul 75
------P	1 Aug 75	31 Jul 76
------R	1 Aug 76	31 Jul 77
------S	1 Aug 77	31 Jul 78
------T	1 Aug 78	31 Jul 79
------V	1 Aug 79	31 Jul 80
------W	1 Aug 80	31 Jul 81
------X	1 Aug 81	31 Jul 82
------Y	1 Aug 82	31 Jul 83
A------	1 Aug 83	31 Jul 84
B------	1 Aug 84	31 Jul 85
C------	1 Aug 85	31 Jul 86
D------	1 Aug 86	31 Jul 87
E------	1 Aug 87	31 Jul 88
F------	1 Aug 88	31 Jul 89
G------	1 Aug 89	31 Jul 90
H------	1 Aug 90	31 Jul 91
J------	1 Aug 91	31 Jul 92
K------	1 Aug 92	31 Jul 93
L------	1 Aug 93	31 Jul 94
M------	1 Aug 94	31 Jul 95
N------	1 Aug 95	31 Jul 96
P------	1 Aug 96	31 Jul 97
R------	1 Aug 97	31 Jul 98
S------	1 Aug 98	28 Feb 99
T------	1 Mar 99	31 Aug 99
V------	1 Sep 99	29 Feb 00
W------	1 Mar 00	31 Aug 00
X------	1 Sep 00	28 Feb 01
Y------	1 Mar 01	31 Aug 01
51	1 Sep 01	28 Feb 02
02	1 Mar 02	31 Aug 02
52	1 Sep 02	28 Feb 03
03	1 Mar 03	31 Aug 03
53	1 Sep 03	31 Mar 04