Table:
text: Affric-Beauly hydro-electric power scheme
Power stations
Power stations
Name_ Year_commissioned Gross_head_metres Installed_capacity_megawatts Average_annual_output_million_KWh
Deanie 1963 113 38 92
Culligran 1962 60 19 59
Mullardoch 1955 27 2.4 8
Fasnakyle 1951 159 69 254
Aigas 1962 18 20 60
Kilmorack 1962 17 20 58

Question: What was the earliest year that the Affric-Beauly hydroelectric system was commissioned with an average annual output of more than 58 and an installed capacity of 20?

Question: What is the average annual output of the Culligran power station with an installed capacity of less than 19 in the Affric Beauly hydroelectric system?

Question: What is the year of commissioning of the power station with a gross head less than 18 among the hydroelectric power stations of Affric-Beauly?

Question: In which year was the power plant with a gross head of 60 meters and an average annual output of less than 59 million kWh for the Affric-Beauly hydroelectric power plant put into operation?