Global Power Transformer Market Report Size, Trends & Growth Opportunity, By Core (Closed, Shell, Berry), By Insulation (Gas, Oil, Solid, Air, Other), By Phase (Single, Three), By Rating (100 MVA to 500 MVA, 501 MVA to 800 MVA, 801 MVA to 1200 MVA), By Application (Residential & Commercial, Utilities, Industrial) and By Region (North America, Europe, Asia Pacific, Latin America, Middle East & Sout