BTSX supply from two consecutive blocks:
{
  "id": 0,
  "symbol": "BTSX",
  "name": "BitShares X",
  "description": "Decentralized Autonomous Exchange",
  "public_data": "",
  "issuer_account_id": 0,
  "precision": 100000,
  "current_share_supply": 199971295850023,
  "maximum_share_supply": 1000000000000000,
  "collected_fees": 30323882455,
  "registration_date": "20140719T000000",
  "minimum_xts_price": {
    "ratio": "0.",
    "quote_asset_id": 0,
    "base_asset_id": 0
  },
  "maximum_xts_price": {
    "ratio": "0.",
    "quote_asset_id": 0,
    "base_asset_id": 0
  }
}
{
  "id": 0,
  "symbol": "BTSX",
  "name": "BitShares X",
  "description": "Decentralized Autonomous Exchange",
  "public_data": "",
  "issuer_account_id": 0,
  "precision": 100000,
  "current_share_supply": 199971296304563,
  "maximum_share_supply": 1000000000000000,