Fix range for Monte Carlo

Please add fix value range for Monte Carlo retest methods - not only percentage range. Percantage range is a problem when we have a diffrent spread of value indicators for example: 5% for indicator with value 10 is something diffrent that 5% for indicator with value 100. In first case the 5% range is to narrow, in second is too wide that's why we need fix value where we set range like form -2 to +2 from original value.