$\text{y - 1975 = 974 + 42017}$
$\text{y - 1975 = 42991}$
$\text{y = 42991 + 1975}$
$\text{y = 44966}$
.
$\text{y - 975 = 112 × 6}$
$\text{y - 975 = 672}$
$\text{y = 672 + 975}$
$\text{y = 1647}$
.
$\text{y - 2009 = 453 × 8}$
$\text{y - 2009 = 3624}$
$\text{y = 3624 + 2009}$
$\text{y = 5633}$