...it shows 2 rings (outer / inner radius 323 / 53, 252 / 89) with 4 gregorian calendar dates in 2 formats each.
(if you want to recalculate:
Annulus Ring Area Calculator Tool : Find Ring Properties)
february 20th 1988 = 202 1988 (202 + 1988 = 2190)
october 15th 1982 = 1510 1982 (1510 + 1982 = 3492)
september 4th 1982 = 409 1981 (409 + 1981 = 2390)
april 9th 1980 = 904 1980 (904 + 1980 = 2884)
(formatting rule for calendar dates would be, if you're interested: "for 'daymonth' use 3 and at least 3 digits whenever possible".)