Translate the following question to SQL: Find the customer who started a policy most recently.

Schema: CREATE TABLE Customers (
    Customer_ID INTEGER NOT NULL  PRIMARY KEY,
    Customer_Details VARCHAR(255) NOT NULL
);

CREATE TABLE Staff (
    Staff_ID INTEGER NOT NULL  PRIMARY KEY,
    Staff_Details VARCHAR(255) NOT NULL
);

CREATE TABLE Policies (
    Policy_ID INTEGER NOT NULL  PRIMARY KEY,
    Customer_ID INTEGER NOT NULL,
    Policy_Type_Code CHAR(15) NOT NULL,
    Start_Date DATETIME,
    End_Date DATETIME,
    FOREIGN KEY (Customer_ID) REFERENCES Customers(Customer_ID)
);

CREATE TABLE Claim_Headers (
    Claim_Header_ID INTEGER NOT NULL  PRIMARY KEY,
    Claim_Status_Code CHAR(15) NOT NULL,
    Claim_Type_Code CHAR(15) NOT NULL,
    Policy_ID INTEGER NOT NULL,
    Date_of_Claim DATETIME,
    Date_of_Settlement DATETIME,
    Amount_Claimed DECIMAL(20,4),
    Amount_Piad DECIMAL(20,4),
    FOREIGN KEY (Policy_ID) REFERENCES Policies(Policy_ID)
);

CREATE TABLE Claims_Documents (
    Claim_ID INTEGER NOT NULL  PRIMARY KEY,
    Document_Type_Code CHAR(15) NOT NULL  PRIMARY KEY,
    Created_by_Staff_ID INTEGER,
    Created_Date INTEGER,
    PRIMARY KEY (Claim_ID, Document_Type_Code),
    UNIQUE (Claim_ID, Document_Type_Code),
    FOREIGN KEY (Created_by_Staff_ID) REFERENCES Staff(Staff_ID),
    FOREIGN KEY (Claim_ID) REFERENCES Claim_Headers(Claim_Header_ID)
);

CREATE TABLE Claims_Processing_Stages (
    Claim_Stage_ID INTEGER NOT NULL  PRIMARY KEY,
    Next_Claim_Stage_ID INTEGER,
    Claim_Status_Name VARCHAR(255) NOT NULL,
    Claim_Status_Description VARCHAR(255) NOT NULL
);

CREATE TABLE Claims_Processing (
    Claim_Processing_ID INTEGER NOT NULL  PRIMARY KEY,
    Claim_ID INTEGER NOT NULL,
    Claim_Outcome_Code CHAR(15) NOT NULL,
    Claim_Stage_ID INTEGER NOT NULL,
    Staff_ID INTEGER,
    FOREIGN KEY (Staff_ID) REFERENCES Staff(Staff_ID),
    FOREIGN KEY (Claim_ID) REFERENCES Claim_Headers(Claim_Header_ID)
);
user
SELECT t2.customer_details FROM policies AS t1 JOIN customers AS t2 ON t1.customer_id  =  t2.customer_id WHERE t1.start_date  =  (SELECT max(start_date) FROM policies)
assistant