vary greatly
vary widely
vary enormously

The course of the disease varies greatly from one person to another.

The type and quality of medical information about a child can vary greatly between countries.

As expected, results vary greatly from one region to another.

From the north to the south, the music scene varies greatly.

A woman's life varied greatly according to her family's social status.

Prices for services, even within the same field, vary greatly.

The time to vote varies greatly from 5 to 20 minutes.

As would be expected in an international market, product life does not vary greatly between countries.

What these workers are finding in the work place varies greatly.

Things can therefore vary greatly from one year to the next because of this.