In 1968 the average salary of men teachers in maintained schools in England and Wales was Â£1,646. I estimate that the last two pay settlements have raised this figure to about Â£1,880. The comparable figure at 31st March, 1963, was Â£1,244.
Two main tectonic structures are spreading centers and subduction zones. Spreading centers occur at the boundary between two plates that are moving apart, called divergent plate boundaries. Here the plate motion opens a gap between the plates and magma from the mantle rises up through it.
The Z-spread, ZSPRD, Zero-volatility spread or Yield curve spread of a mortgage-backed security (MBS) is the parallel shift or spread over the zero-coupon Treasury yield curve required for discounting a pre-determined cash flow schedule to arrive at its present market price.ince the Z-spread uses the entire yield curve to value the individual cash flows of a bond, it provides a more-realistic valuation than an interpolated yield spread based on a single point of the curve, such as the bond's final maturity date or weighted-average life.