text: ---------- IncomeData table ----------
  
  CREATE TABLE tax.income_data
  (
      id           VARCHAR   NOT NULL PRIMARY KEY,
      tax_payer_id VARCHAR   NOT NULL,
      received_at  TIMESTAMP NOT NULL,
      amount       DECIMAL   NOT NULL
  );
  
  ---------- TaxType table ----------
  
  CREATE TABLE tax.tax_types
  (
      id          VARCHAR NOT NULL PRIMARY KEY,
      title       VARCHAR NOT NULL,
      description VARCHAR NULL
  );
  
  ---------- TaxLayer table ----------
  
  CREATE TABLE tax.tax_layers
  (
      id         VARCHAR   NOT NULL PRIMARY KEY,
      type_id    VARCHAR   NOT NULL,
      percent    DECIMAL   NOT NULL,
      min_amount DECIMAL   NOT NULL,
      max_amount DECIMAL   NOT NULL,
      valid_from TIMESTAMP NOT NULL,
      valid_to   TIMESTAMP NOT NULL,
      foreign key (type_id) references tax_types (id)
  );
  
  ---------- TaxData table ----------
  
  CREATE TABLE tax.taxes
  (
      id           VARCHAR   NOT NULL PRIMARY KEY,
      type_id      VARCHAR   NOT NULL,
      tax_payer_id VARCHAR   NOT NULL,
      payed_at     TIMESTAMP NOT NULL,
      amount       DECIMAL   NOT NULL,
      foreign key (type_id) references tax_types (id)
  );
  