How to set custom pagination range?

I was trying to scrape the name and email of teachers in this site. It has 128 pages and for some reason, the scrapper stops at around 250-350 data. I think it's my internet connection. So how can I set the scrapper to only scrape data from Page X to Page Y? So I can set batches in order to avoid errors due to discontinuation.

Url: https://www.lexrich5.org/site/Default.aspx?PageID=13505

Sitemap:
{"_id":"NameEmailMultiplePages","startUrl":["Lexington-Richland School District 5 / Homepage a","type":"SelectorPagination"},{"id":"Container","multiple":true,"parentSelectors":["Pagination"],"selector":"div.staff:nth-of-type(n+8)","type":"SelectorElement"},{"id":"Name","multiple":false,"parentSelectors":["Container"],"regex":"","selector":"li.staffname","type":"SelectorText"},{"id":"Email","multiple":false,"parentSelectors":["Container"],"regex":"","selector":"a.bb-icon-ultra-mail","type":"SelectorText"}]}