month	level
ja96	578.64
fe96	578.71
mr96	578.71
ap96	578.94
my96	579.49
je96	579.92
jl96	580.15
au96	580.18
se96	580.12
oc96	580.05
no96	580.02
de96	579.95
ja97	580.02
fe96	580.12
mr97	580.35
ap97	580.54
my97	580.94
je97	581.10
jl97	581.33
au97	581.23
se97	581.10
oc97	580.77
no97	580.35
de97	580.02
ja98	579.86
fe98	579.76
mr98	579.86
ap98	580.35
my98	580.41
je98	580.38
jl98	580.31
au98	580.05
se98	579.66
oc98	579.23
no98	578.87
de98	578.61
ja99	578.31
fe99	578.35
mr99	578.22
ap99	578.25
my99	578.35
je99	578.54
jl99	578.74
au99	578.61
se99	578.22
oc99	577.89
no99	577.56
de99	577.40
ja00	577.17
fe00	577.00
mr00	577.10
ap00	577.17