Dear Sudhir12345,
The above pay scale says as under:
The salary of the clerk in the beginning is Rs. 325.
There is an increment of Rs. 20 every year to him for five years or till his salary reaches to Rs. 425.
After that the rate of increment is of Rs. 25 every year for next five years or till his salary reaches to Rs. 550.
After that the rate of increment is of Rs. 30 every year for next five years or till his salary reaches to Rs.700.
After that the rate of increment is of Rs. 35 every year for next six years or till his salary reaches to 910.
Then the increment rate is Rs. 40 for next six years or till his salary reaches to 1150, Rs. 45 for next five years or till Rs. 1375, Rs. 50 for next five years or till Rs. 1625.
His last salary would be Rs. 1625. There is a stagnation.
This pay scale is for the tenure of 37 years maximum.
There is no bar on getting more than single increment on performance / efficiency. In that case the tenure of the scale will be shorter and at Rs. 1625 there is a stagnation unless there is a revision.
This kind of pay scale pattern is now out dated in private sector.
There is also a concept of EB in between. EB means efficiency bar.
Hope I have explained this properly.