Table:
| Years Ended December 31, |  |  |
| --- | --- | --- |
|  | 2019 | 2018 |
| Beginning balance | $ 738.7 | $ 243.5 |
| Less: recoverable from reinsurers | (136.4) | (100.6) |
| Beginning balance, net | 602.3 | 142.9 |
| Opening balance due to business acquired | — | 295.4 |
| Less: recoverable from reinsurers | — | (55.9) |
| Net balance of business acquired | — | 239.5 |
| Incurred related to insured events of: |  |  |
| Current year | 211.8 | 216.6 |
| Prior years | (47.2) | 81.6 |
| Total incurred | 164.6 | 298.2 |
| Paid related to insured events of: |  |  |
| Current year | (17.5) | (15.0) |
| Prior years | (141.0) | (72.1) |
| Total paid | (158.5) | (87.1) |
| Interest on liability for policy and contract claims | 21.9 | 8.8 |
| Ending balance, net | 630.3 | 602.3 |
| Add: recoverable from reinsurers | 131.0 | 136.4 |
| Ending balance | $ 761.3 | $ 738.7 |
Paragraphs:
The Insurance segment experienced a favorable claims reserve development of $47.2 million and an unfavorable claims reserve development of $81.6 million for the years ended December 31, 2019 and 2018, respectively.
The main drivers of the current year favorable development were due to an update to the estimate for remaining benefits to be paid and due to favorable development in claim termination rates experienced relative to prior years.
The main drivers of the prior year deficiency were post-acquisition recapture of two reinsurance treaties on the KIC block, post-acquisition reserve strengthening on the acquired KIC block, and variance in the development of claim termination rates and care transition settings on prior year incurred claims.
Question:
What caused the prior year deficiency?