RoboGarden sells a robot lawn aerator. At the current price, RoboGarden's contribution margin is $134.60 per unit. Because of a shortage of silicon chips, RoboGarden expects variable cost to increase by $12.39. In response, RoboGarden is thinking about raising its selling price by $21.83. Calculate the percent profit breakeven metric for this situation. Report the correct sign for the result. Report your answer as a percent. Report -25.5%, for example, as "-25.5". Rounding: tenth of a percent.