feat(security): add collateralization ratio attribute

documentation/properties/cover_pool_balance.md

@@ -0,0 +1,15 @@
+---
+layout: property
+title: "cover_pool_balance"
+schemas: [security]
+---
+
+# cover_pool_balance
+
+---
+
+The balance of the cover pool securing the covered bond.
+
+Cover Pool means a clearly defined set of assets securing the payment obligations attached to covered bonds that are segregated from other assets held by the credit institution issuing the covered bonds.
+
+See [ECB Working Paper No 2393](https://www.ecb.europa.eu/pub/pdf/scpwps/ecb.wp2393~f0796c2019.en.pdf)

v1-dev/security.json

@@ -105,6 +105,11 @@
       "description": "Two-letter country code for security location/jurisdiction. In accordance with ISO 3166-1.",
       "$ref": "https://raw.githubusercontent.com/SuadeLabs/fire/master/v1-dev/common.json#/country_code"
     },
+    "cover_pool_balance": {
+      "description": "The balance of the assets that are held in the cover pool",
+      "type": "integer",
+      "minimum": 0
+    },
     "cqs_irb": {
       "description": "The credit quality step for internal ratings based approach.",
       "type": "integer",