An investor holds shares of Bank of Montreal. The Canadian stock market can be explained by three sources of systematic risk: short-term interest rates (I), the rate of inflation (P), and industrial production (Y). Short-term interest rates have an associated risk premium of 5%, inflation has an associated risk premium of 6% and industrial production has an associated risk premium of 1%. Each systematic factor has a mean value of zero, so that non-zero factor values represent unexpected surprises from prior expectations.

The excess return for the stock can be described by the following formula: R = 0.13 + 0.8 I + 0.3 P + 1.1 Y + e

What is the stock's alpha according to the APT? Enter your answer as a decimal number or with the percentage sign.