A company current operations allow the company to make $1000$ boxes per day, in two $10-$hour shifts $(500$ boxes per shift$).$ The company has introduced some small changes in equipment, and conducted appropriate job training, so that production levels have risen to $600$ boxes per shift. These changes did not require any change in the amount of capital spending or energy use. What is the firm's old labour productivity, new labor productivity and also indicate if there is any percentage change in productivity?