Looks like you are new to YT so..... Welcome. This is such a great site there is alot of information here, and alot of people that are willing to answer question.
This is a chart that was done by one of our members, she is a breeder and has her own site. Just click on the link below and it will take you there. The second link is for people new to YT. It has alot of helpful information.
Growth chart
http://yorkiepassion.com/growthchart.htm
For new people
http://www.yorkietalk.com/forums/sho...ighlight=amber