What is meaning of Elastic Stretch of wire?

Note :

For 16mm dia. wire rope – Elastic stretch under load, expressed as a percentage of the length of the wire under load, will be:-

Wire
6 x 12 = Load (in tonne f)/6 — % stretch
6 x 19 = Load (in tonne f)/lO — % stretch
6 x 24 = Load (in tonne f)/8 — % stretch.

For 18mm dia. wire rope –  Elastic stretch under load, expressed as a percentage of the length of the wire under load, will be:-

Wire
6 x 12 = Load (in tonne f)/7.7 – % stretch
6 x 19 = Load (in tonne f)/l3.0 — % stretch
6 x 24 = Load (in tonne f)/l0.4 — % stretch