How to identify the original coverage start date in the plan type ?

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When each life event run, the coverage through date is updated to LE - 1 day even though there is no change in enrollments. The coverage start date gets reset to the new LE date. The original coverage start date also changes each time the employee changes plans within the same plan type. Is there a way /column where original coverage start date within the plan type is tracked. Ie, Employee enrolls in Plan 1- Emp only options on 1/1/2020. 6/1/2020 he moves to Plan 1 - Employee + One option. On 1/1/2021, Employee moves to Plan 2 - Employee