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                        1. Number of non-sunny days in 1 month 
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                        2. Duration of sunshine for 1 year 
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                        3. The actual proportion of sunshine duration is possible (the actual ratio of sunlight to sun is possible) 
1. Number of non-sunny days in 1 month
2. Duration of sunshine for 1 year
3. The actual proportion of sunshine duration is possible (the actual ratio of sunlight to sun is possible)